Mostly, I do not like Travis because he is violent and angry. Also, I hate that Travis had such a lack of loyalty to his brother Emmett, that he would move in on Bay romantically (someone Travis knows to be the love of Emmett's life), as soon as Tank's violation of Bay caused problems in Bay and Emmett's relationship.
Plus, Travis had no business bringing alcohol to that dorm party with underage students.
And Travis should have looked out for Bay, seeing as Emmett was 2000 miles away and Bay was hanging out with her ex-boyfriend and so drunk she couldn't stand up. Travis knew that.
Travis was the one who sent Tank and Bay to a bedroom. Every other guy at the party knew that Bay and Tank were about to hook up. Why didn't Travis know that? Why couldn't he look out for Bay and Emmett? It was just a few months earlier that Travis saw Tank take a serious swing at Emmett, while they were all at Scratch. Travis knew that Emmett and Bay slept together at Rivas Canyon, while Bay was still dating Tank. Travis didn't think that Tank might not be the safest person to send to a bedroom with a drunk Bay?
During the uprising, Travis didn't want Bay to attend Carlton their senior year, despite the fact she is the one who pulled the fire alarm and made the art for their movement. Even Natalie accepted Bay, but not Travis.
Travis bullied and teased Noah, and then hit him when Noah finally spoke up for himself.
Travis wanted to play the vigilante part when Daphne's food truck was robbed. He lied to the police about what he had seen, so he could beat up one of the guys who robbed them.
Travis wanted to sue John for firing him, after Travis cussed out one of John's best customers.
There's more, too, but those are the highlights.
I could enjoy Travis being friends with Bay and Emmett, if he would actually be a friend to either of them. I didn't care for how he kept manipulating what he wanted to happen, at Bay's expense this last season. It was completely inexcusable that he told Garrett about what happened between Bay and Tank. That should have been Bay's decision whether or not to tell Garrett. It was completely selfish and insensitive for Travis to do that to Bay.