My wife and I have done most of our cruises with just the two of us. We have not had a bad experience when
DCL has assigned us to a table with other people. Made good friends on one cruise with a couple from New Zealand and are still Facebook friends with them. Unfortunately we have not been able to coordinate another visit with them yet.
My wife was disappointed when on the last couple of cruises we were seated by ourselves. After hanging out with me all day, she looks forward to talking with other people

. I think we may have actually asked our TA to request that we be assigned to a table with other people, but it didn't happen.