As the moderator of a Reddit sub focused on comp sci careers, I don't think the open office is an issue for junior level developers. The worship of what we in that sub call the big 4 (some combo of Google, Facebook, Apple (or Microsoft), Amazon) is pretty much what you hear from every college senior, and I've never heard anyone even mention this as a negative. Of course these are mostly people who haven't had much ex…
I don't get your point? Like you say, a bunch of people who have never worked in an open plan office obviously won't complain about it, nor will they realize it's something they should filter by. They haven't experienced the problem yet. Take renting a flat. I now know to avoid everywhere with storage heaters, just like I avoid places with single glazing and I also now know I should check the shower water pressure. I…
There are plenty of people who are biased about things (like an open office environment) they haven't personally experienced, yet hold their bias based on hearing about the experiences of others.
I've never been in an airplane crash, and I'm pretty sure I never want to be in an airplane crash. I don't need to personally have that experience to have a bias against it.
If you didn't know about storage heaters or single glazing before renting a flat, there are probably a number of ways you could have discovered those things without having to experience them directly. It certainly wouldn't require "magic" as you say.
If a bias against open offices is happening, it doesn't seem to be impacting our newest industry entrants yet.