Is being agreeable and having no backbone a good reason to break up with someone?

Not only my first boyfriend broke up with me because I’m on the autism spectrum but also because he says, its an embarrassment having a bigger and talIer girlfriend, agreed with everything he says, well some things, I butter up (sugarcoat) things than to be blunt and straightforward. That irritated the crap outta him and also he said I had no backbone and he can’t be with a girl that can’t stand up for herself and let people walk over her. You’re a “yes” person and you can’t even be honest and I shouldn’t have to drag an opinion outta you!” He treated me like garbage and I took it. He looked at me saying, “REALLY?! Are you seriously going to let me treat you like this?! Your dad is right about one thing about you. You’re WEAK!” And just walked off. He cheated on me with another girl and he broke up with me over video chat and the girl he cheated on me with is petite and not tall and broad like me.