Stick with your main or you're wasting my time. Most of the time, it's not that the person is generally much better at the game, I just don't know shit about the character they're playing. Especially nowadays, with all these bloated rosters
If you're not giving the person a chance to learn the matchup, then you don't really know where that person stands in relation to you if you're beating them. If they're generally scrubby - constant Reversals on wakeup, no optimized damage, no anti-airing, not teching obvious grab setups, etc. etc., then that's a little bit different, because as the clearly better player, you will get bored. But even still, you'd be helping that person a ton in improving if you introduced less variance into the set, regardless. I'd like to think that people would want to help others get better.
If you're not giving the person a chance to learn the matchup, then you don't really know where that person stands in relation to you if you're beating them. If they're generally scrubby - constant Reversals on wakeup, no optimized damage, no anti-airing, not teching obvious grab setups, etc. etc., then that's a little bit different, because as the clearly better player, you will get bored. But even still, you'd be helping that person a ton in improving if you introduced less variance into the set, regardless. I'd like to think that people would want to help others get better.