Sure, that is a downside, however what is there to play on a game/s that is based on MMO? Playing against a computer or by yourself is very lackluster.
Now there are some few custom games i can get behind, that are still playable alone. however extremly few and often funnier with more people.
"having a choice would probably be the answer to this reply however, the benefit that it takes away, from those small gathering places. Where people play and still probably do on local area network, to the bnet.