My wife and I are performing magicians. The topic of "exposure" can get downright stupid.
Something you hinted at is intellectual property rights. Like you said, a lot of magicians market their inventions. And so if a "peer" of theirs were to explain the method to someone who didn't purchase it then it would be viewed as a dick move since it is affecting the livelihood of a fellow performer. For what it is worth, this is a position that I agree with. I don't market or publish my work but if I did I would be seriously pissed off from an intellectual property point of view if other people were giving it away for free and undercutting my ability to sell a "license" to perform my artistic creation.
Where it gets stupid is when it comes to stuff that anyone can find in a book on Amazon or in a kid's magic kit. This is a mentality that I just cannot wrap my head around. Knowing what a thumb tip is, or how it can be used, has not ruined magic for people ... if it did, no one would pay to see a show. You go see a show to be entertained and surprised.
The reason we don't "reveal" is purely artistic. When you go a see a movie, you go in willingly suspending your disbelief. But magic is more of an intellectual challenge. The entire point is to cause a jaw-dropping "that can't be possible" moment. To achieve that you go in kind of wanting to have your disbelief suspended for you. A revelation in the moment destroys that[1]. But life is way too short for the average person to give the slightest crap about how something works when they go home and have to worry about getting up in the morning to go to work or getting their kids from the babysitter.
And the genuinely curious are often the future generation of magicians.
So yeah, the magic community can be utterly illogical when it comes to this.
[1] - Unless it doesn't. To bring this back to Penn & Teller, something Penn once said is (paraphrasing) "A trick that has a method that is more interesting than the effect is not a good trick." P&T do more than one routine where they show the effect and then the method. They do this because, artistically, these are cases where knowing the method makes it even more spectacular and amazing because the method itself is genuinely interesting. Their cups & balls routine is probably the most famous example.