I agree here; we as Windows users are being forced to use the HomeGroup feature with no ability to turn it off. I have a 24/7 home server at my house and have reasons for wanting to use advanced sharing features (e.g. in some cases I want a specific
user to have read-only access to certain shares or folders). I do not like seeing the HomeGroup folder show up in Windows Explorer when it isn't being used.
On another note - I also hate seeing the "My Documents/Music/Pictures" etc as well because I don't believe in storing important items such as this on a PC (versus a server with multiple levels of backup).
I think that these features have their place with inexperienced users however without the ability to turn this off gives the experienced users a bad experience.