Sure, quit social media if you're a robot who's sole purpose in life is to maximize your career - though I'd still argue that social media is valuable in that it enables you to expand your network and maintain/strengthen your personal connections. But even if it were the case that social media is worse for your career, a lot of us live for more than our careers.
If you find yourself constantly wasting time on Facebook during work, you just lack discipline. I don't know about you guys, but my news feed is generally pretty boring, thus I don't have the urge to keep checking it. I'm not trying to claim moral superiority here, just saying that if you have an addiction problem, you need to take responsibility and hold yourself accountable rather than blaming the tool.
I bounce back and forth on this. I don't really feel like Facebook enriches my personal connections; it just lets me remain to a lot of people I'm not really connected to anymore. It's like having a system for maintaining lower tier friends. LinkedIn feels the same way: I have a huge network of people that are all talking, but none of it really does anything to enrich my career. I don't listen to them, they don't listen to me. When I need career advice, help with job hunts, etc. I call someone I know and trust and they do the same. I don't think we can feasibly maintain large networks.
I have found a large LinkedIn network to be useful for finding customer interviews for startup ideas. There are a lot of people that I am connected to enough that an intro from them beats a cold email. I often will find a company that seems like a good fit for a problem or idea I am working on, see if I have any second-degree connections there, and ask for an intro.
I really enjoyed Brad Feld's post[1] on choosing how to use each social network you sign up for. On LinkedIn, I've decided to be a public, promiscuous consumer. On Twitter, I am public, selective, and a mix of consumer/producer. Facebook is one that I probably need to cut even more than I do, since I don't have a strategy and get little value from it.
Social networks can be tools, and if they are not providing value, it may mean you need to use the tool differently or get rid of it if it doesn't solve a problem you have.
If you find yourself constantly wasting time on Facebook during work, you just lack discipline. I don't know about you guys, but my news feed is generally pretty boring, thus I don't have the urge to keep checking it. I'm not trying to claim moral superiority here, just saying that if you have an addiction problem, you need to take responsibility and hold yourself accountable rather than blaming the tool.