People just ditching Fedora for another distro is exactly what is being warned about on the linked forum thread, should the Fedora team decide to go through with it.

As for the why; the Fedora team says that 32bit libraries are annoying to maintain and that they can cut it out to save on time and resources. They consider 32bit old and no longer relevant.

However, others have said that if 32bit is still being used (also for none-game-related projects) then it's still relevant and should still be maintained. Also that Fedora should develop according to what the user base wants, and not pull a Microsoft/Apple and force want they want on the user base.