There are limited situations where I as a user really do want pinch-to-zoom disabled. Primary example would be browser-based games. Depending on what gestures the game uses, I sometimes end up zooming accidentally on mobile, which is super annoying.
Id prefer a "lock zoom" button in the browser, but I understand that may not benefit someone who never opens a browser menu and just wants a website to work.
The problem with adding buttons is that you end up with a lot of buttons. Which is then a cause of people not opening browser menus.
Separately, it makes more sense to me for websites to set the default they think is best, and then let users override it. This can be done today in any browser with a bookmarklet.
(None of this is to excuse websites which abuse their power. I just don't think removing that power is the right solution, at least not here.)
