Well Cabba alone makes your statement false, but I dunno how you figure everyone else is bad.
I'm mostly judging by their Hakaishins and the few individuals that have had a presence so far. I know the nature of the tournament itself forces them to be cruel, but there legit hasn't been a single pleasant fighter. Even the lovey dovey U2 seemed kinda villainy.
Universe 3? A robot army spearheaded by a mad scientist
Universe 4? Their pre-tournament actions were totally villainy
Universe 6? Spearheaded by a dude that kills for money and a Freeza clone.
Universe 7? Legit 9 assholes+Gohan. They even had a spare asshole to replace the asshole that went in hibernation!
Universe 9? Duh, so much bad blood
Universe 10? The superficial universe shaped by Gowasu obsession with YouTube views and Zamasu's insanity.
It's no wonder the mortal quality rating of these universes are so low and Pappa Whis and Zeno want to get rid of these universes.
Universe 7 in particular is amateur hour, only second to Universe 9.