How can I remove the Facebook and Twitter components from OS X?
(Similar to removing the People" component from Windows 8).
You can't remove these services, at least not in a reasonable way. Now, you might ask, why keep something you don't need?
Well, because it's tightly integrated into the system and would require major efforts to get rid of. This is not even considering possible bugs that would occur when components are removed and your OS starts looking for them.
Having the possibility to log into Facebook or Twitter is not taking away precious hard drive space—at least not a significant amount. We're talking about a few megabytes maybe. Furthermore, it does not consume resources when not used.
That being said, if you're up for it, you could of course search around
But don't say you weren't warned if you start removing files from there and something in OS X breaks.