Using it and liking it aren't the same thing. Shedloads of people here use Facebook, and a fair percentage of them would no doubt gleefully criticize it given half a chance.

And there's also tons of people who don't necessarily like using the service, but somewhat forced to for a number of reasons. I, for one, don't find the service that useful, however, most employers find it particularly odd if you don't have one.

So, you're kind of put into an odd position by electing to go against the service in this day and age. Granted, no one is putting a gun to your head and telling you to use LinkedIn. Yet societal pressures (specifically in professional circles) have somewhat made it difficult to go against the grain.