My employer does this sort of thing, but it isn't mandatory. A sign-up sheet goes up in the kitchen, and there's never a lack of participation. From what I've seen, folks seem to genuinely enjoy doing this sort of thing, so more power to them. Sometimes I take part, sometimes I don't.
Now, if we were forced to participate, that'd be another matter.
My social life is just fine, thanks. I don't need a boss telling me who my friends should be.