You don't have to see something to hate it, especially with media. But, to be fair, I sure as hell "saw" those tumorous abominations they're calling klingons. I also saw the trailers and everything else they've shown. So, I hate a lot of things, all based on what they've shown and talked about.
As for he's talking about, I may see the show but so what? People hate watch things all the time. My watching won't support the show, and its Star Trek. The fact that they've made a version of Trek worse then the 09 movie (as much as I love Beyond, I'll always hate ST09) or literally anything the TV show ever did makes it a must watch just for people like me who have a lot of morbid curiosity. He's shitting on fans of a show because they don't like the name being slapped on some crap sci fi show that is no more Star Trek then it is Guardians of the Galaxy or Doctor Who. His opinion might piss me off, but its also the meaningless opinion of a completely clueless person.