This has been debated before. The truth is that there are libre games for
almost all the platforms that those emulators you mention support. Do people
really play those instead of the proprietary games? Maybe not. But the
possibility exists and therefore shouldn't be removed.
Also, I would be disappointed if I couldn't find an emulator for old systems
such as SNES and Genesis. Those games have no internet connection, no way to
escape the "sandbox" of the emulator itself, and have a nostalgic value for
most users, they are not merely games as much as they are showcases of how we
got here in terms of gaming industry. For these reasons, emulators are seen
as being a tolerable less than ideal option.
I understand your opinion and respect it, though I don't see reasons hard
enough to remove those.
Other users can help you find libre games for those emulators and a quick
internet search will also help you.
