No, I actually interact with them more. I hate the phone and am often extremely busy, so I never really called anyone before anyway. I still visit whenever I can, but for some people that may mean years before I see them again. Facebook lets me interact with them within my time constraints and still be a part of their lives. My best friend often "visits" me on Skype now, so that might be a way to increase some face time -- she can't afford to come to Wyoming, and I can't go to Florida to see her, so we use what we have.
One caveat -- I am careful about how many people, and what type of people, I have on my Facebook. I don't "friend" everyone with whom I'm acquainted, and I will "unfriend" for persistent drama, negativity, or just plain being boring. It's not that I mind them posting those on their wall, that's totally their space, it's just that I have no interest in seeing it on my timeline. I see some people with like 800 Facebook friends and it totally swallows up their lives. My own list stays around 150, mostly family members, close friends, classmates and a few clients, as well as a few positive, interesting people I've met in my "internet travels."
Without Facebook, it's very possible that I'd just stay in my own little world indefinitely without interacting with anyone else at all. I work from home, I'm quite comfortable in my own skin and enjoy my own company, so there's not much push to keep in contact with people. When I know I can "shut off" the socializing whenever I need to or want to, then I don't mind jumping in for 5-10 minutes here and there.