It's not 0/1 problem. Obviously being asshole for no reason is bad.
But bending over backwards for bad solutions just coz you "don't want to rock the boat" or "don't want to argue" leads to mediocre product driven by whoever happens to be least polite in the team. Tiny bit off stubborness and assholery on stuff you know is right (as in when nobody can provide actual sensible arguments for other way) can be very helpful.
Also I did worked with "toxic but brilliant" ones and honestly I vastly prefer it over nice useless people. Toxicity can be managed, uselessness can not.
But bending over backwards for bad solutions just coz you "don't want to rock the boat" or "don't want to argue" leads to mediocre product driven by whoever happens to be least polite in the team. Tiny bit off stubborness and assholery on stuff you know is right (as in when nobody can provide actual sensible arguments for other way) can be very helpful.
Also I did worked with "toxic but brilliant" ones and honestly I vastly prefer it over nice useless people. Toxicity can be managed, uselessness can not.