i usually don't like to play with people who don't know how to play poker for three reasons-
1.) like you said, you have to explain the rules
2.) you don't get any better playing these type of players
3.) its hard to bluff someone who doesn't know what they're doing, or simply put, its hard to bluff at lower limits because players have a tendency to call more.

However, someone could easily counter this argument by saying that if you play with horrible players, you win money. Question comes down to - in this particular tournament, am i playing to get better or make money?