I recently had a discussion that kind of touches on this issue and a couple of the things I've seen in the above likewise hit the proverbial nail on it's nogg'n
MONEY & POLITICS are two of the biggest factors here, when it comes to which is viewed as being "more right than wrong". If you don't stand in good favor with certain political elements within magic and you have an effect/method that is "obtained" by someone that is better connected after the fact... you loose!
Eddie Joseph, for an example, is better known for PREMONITION than its actual originator, George Armstrong. . . was Joseph just stealing something neat and taking credit for it, or was he "exposing" Armstrong's effect?
Then too, you have the social associations; Armstrong gains stronger recognition & endorsement in the UK (primarily) where Joseph's accolades exist mainly in the States where Percy Abbott promoted his name (while making things
look legit)
In other words, perspective along with who is getting the greatest sense of benefit and who has the strongest standing social-political recognition, can have a lot to do with the issue of both, thievery and/or exposure.
But Then We Have Magic Books. . . :twisted:
During that "Golden Era" of magic (mid-1800's through the late 1920's) many of those greats were complaining about publishers making magic books to easy for the general public to get their hands on (sound familiar?)... Harry Houdini seems to have been one of the more outspoken on the issue even though, for PR reasons, he penned a few of his own. Then again, nearly all of the yesteryear greats produced at least one small Pitch-Book sold at their shows with several (Dante, Blackstone & Mandrake most particularly) had comic books in which tricks were explained.
I believe it was Kenton Knepper that did an article about a decade back, addressing this issue and the fact that there is not a single major name in magic who isn't guilty of "exposure". One of David Copperfield's early year PR bits was "Project Magic" in which simple tricks were taught to people (senior's mostly) as a form of physical therapy; Blackstone teamed up with Oreo Cookies as well as Jiffy Pop and other such companies over the years with live shows, premiums and "lessons" in how to do magic... Mark Wilson did the Magical Burger King promotion in the 70's that again, taught magic in a very public manner. . . there's the Ronald McDonald shows that have given away tricks as well as booklets like
101 Magic Tricks You Can Do (which were a common give-away for Birthday Show performers for decades). . .
So... why are all of these demonstrations of blatant exposure "OK" while the Boobs on YouTube aren't?
#1 -- Look at the money & the Brand Names (clout)
#2 -- The fools on YouTube are simply idiots that have NO respect for magic or magicians. It is this lack of respect that I feel, pizzez most of us off (aside from the fact that most get bent when a piece they just dropped good money on is suddenly FREE TO ALL)
BALANCE is the important thing!
A degree of exposure is actually healthy in that it brings new blood into the craft; this is what the bulk of the methods & routines shared by both Blackstones, Dante, Wilson, etc. did; it planted seeds that fueled the imagination. Those little premium tricks and booklets given away by the birthday performer does the same exact thing while likewise allowing him/her to befriend the kids and over the years, cultivate a multi-generational market advantage. . . not to mention availability for teaching kids how to do magic and to help the more talented to rise to the top by getting them into the clubs, etc.
Even having books in the public library or in noted book stores like Barnes & Noble, has its advantages when it comes to sustaining and evolving magic. The important point to bear in mind here is the fact that rarely will anyone buy or borrow those books UNLESS they have a genuine interest in learning about Magic vs. "a trick"
The downside is where the imbalance exists; Bit Torrent/File Share networks along side the philosophy that
"Information Should Be FREE to Everyone No Matter What It Is" (thank you Wikileaks & Friends). Worse, are those that steal material that belongs to others, for the sake of personal gain, be it financial (by selling copies of said material on eBay or similar sources) or by using the material in Barter for other bootlegged material. Sadly, such situations have resulted in the more innocent act of borrowing & loaning books/discs between friends & club members a negative thing, but innocents always seems the thing lost quickest when gross abuse comes to the fore... again, the issue is cash in pocket.
Abuse is the Key and WE (all of us) are part of the problem. Our desire to possess any and all we can get our grubby paws on is why these File Share sites are so abundant and worse, why they have so much material that belongs to most every industry out there. . . though everyone denies it, someone is supporting such things or it wouldn't be and the "shared" files wouldn't be accessible/posted. . . or the bootleggers in business. This is the great truth most of us ignore and I'm betting it's due to guilt in one form or another.
The Masked Magician type exposure is a touchy issue for me in that Val was a dear friend at one point in time (and no, it wasn't his shows that changed things, just distance and time with lots of "life" getting in the way). His logic for the original 6 or so shows was something more than a few notables actually supported at first. . . and if you look around, his "challenge" seems to have been heard given how far and fast illusion design (grand illusion, not hand tricks) has changed; stepping away from the older, more "traditional" modes we relied on for well over 100 years -- magic has benefitted!
The new version of the Masked Marvel I do have issues with in that he is exposing some of the newer (less than 30 year's old) systems vs. the older "Vaudeville era" pieces seen in the original series). I believe that the more contemporary technology MUST stay as secret as possible so as to protect the people whose livelihood depends on it; no one takes things lightly when a $10,000.00 prop is exposed on national TV. It's not just the lost value in the effect but the investment suddenly looses its value as well. I don't know about you, but 10 grand out of most people's pockets isn't something to take lightly; especially when the majority of magic buffs rarely own a brand-new grand illusion and at that, few own more than 6 such pieces in their life-time. . . and that's before you get into those effects popularized from the mid-1980's to present.

Pardon the rant
I do however hope this shines some light on the issue for you and anyone else that's willing to weigh things.