Sparring isn't a social event. Never will be and never has been something where you can claim you are good or claim that someone is bad just by saying it. You can't chat your way into having a reputation as a sparrer, and I won't even get into a list of people who stress over trying to do it because I find it sort of embarrassing.
You're a bad sparrer when you lose over and over and make excuses for it. You're bad when you refuse to blame yourself, because you're not even making an attempt at taking up some responsibility and improving. You're a very awful sparrer when someone beats you and you immediately resort to bringing up your iOS keyboard to frantically type "OMG NOOB" or "OMG DELAY" as fast as possible. You are probably a bad sparrer if you spend half of your time in the Battle Arena chatting instead of sparring. There's a really, really good chance that you are an overrated, average-tier, unconfident sparrer if you literally stress over spar points and feel so overwhelmed with joy when you finally reach the #1 spot that you can't resist but make a status about it.
You are a good sparrer if you beat people and don't cry and make excuses when you lose. I don't even know how you can question if someone is a good sparrer. It's pretty easy to prove. If someone were to call me a bad sparrer, I'd tell them that I am better than them and then make multiple efforts to prove it and embarrass them, because that's the only thing enjoyable to me in this game. If someone consistently beats you, and others, you're dumb for saying they're bad. If you're too scared of scarring your reputation on this bad game and refuse to even spar them and would rather gossip and talk about them then you're a fan.
Even if you have a trash attitude, the social part of the games means 0 in the sparring community. That is why I can say Zeross was a good sparrer on PC. His attitude was disgusting and he behaved like a clown, but he would beat you in a spar. If you're cocky or arrogant then it doesn't matter, no one can take away the fact that you can beat them straight up in a spar. All they can do is whine about it.