Since all my Linux servers are Samba servers or accounting servers serving terminl emulator logins I don't make a separate /home, but I do make a separate /u partition where all the accounting data and all the Samba shares reside, and where copies of all the special driver and application files I've added and copies of all the scripts reside.

For a desktop machine I'd definitely have a separate /home partition because most desktop applications store all their stuff there.

And no, I never depend on backups if there is any alternative.