I'll tolerate communal dining if that's what a place I want to visit offers but I'd never, ever seek it out. For me, it's a check in the negative column when deciding where to eat. Sharing a table with people I don't know is of very limited -- or even negative -- value to me. And being the relatively anti-social person that I am, I find it pretty awkward, too. It requires additional levels of effort and social interaction on my part. It's an artificial situation created mainly for the eatery's financial benefit. If, at 99% of places offering communal dining, more net revenue would be gained via non-communal dining, you can bet that's what would be offered instead. But more diners, faster turns and fewer staffers required all make communal dining an alluring choice for operators.
Some places have big tables at which the separate parties who share them are not really synched up in any way. For me, this is the most tolerable form of communal dining. At these places, folks come and go on their own schedules. Diners can order what they want, eat at their own pace and share the dining experience with their neighbors only if they choose to do so. This is as good as communal dining gets but it's still not a particularly desirable experience.
Other places synch up communal tables from beginning to end, including everyone at the table being served the same menu. For me, this is the hardest form to deal with. What if I'm late (
as has happened)? What if my tablemates are late (as I've also experienced)? What if they start talking about politics? What if they're loud or obnoxious? What if they get pissed because I slow the meal down taking pictures? What if I just don't like them? What if, over the course of my meal, I want to chat with the companions I've actually chosen about personal stuff? At a synched up communal table, all these issues are in play -- and for no good reason. This form of communal dining artificially forces the experience to be mostly about the experience itself, and not much else -- and I say this as someone who is fairly food-centric. The bottom line is that when the food's truly great, no such manipulations are required to keep diners engaged and focused. I'm just not a big fan of The Dining Table as a petri dish.
As for benches and picnic table-style seating (which may or may not be a part of communal dining), don't even get me started!

=R=
By protecting others, you save yourself. If you only think of yourself, you'll only destroy yourself. --Kambei Shimada
Every human interaction is an opportunity for disappointment --RS
There's a horse loose in a hospital --JM
That don't impress me much --Shania Twain