Ofcourse, you're free to like it and I also like dumb things sometimes too. Fanboy and ChumChum being the biggest example of that, but difference is while Fanboy and ChumChum was an original show with it's own ideas Thundercats Roar is not. It's taking a franchise that was all about action and turned it into a joke, just like Teen Titans Go. So ofcourse the fans are going to be heavily disappointed and some even angry. I'm one of those people who grew up with Transformers Animated and despite the change in the artstyle from the original G1 Transformers people still loved it because the creators stuck with what made Transformers work.
I'm not really a huge fan of Thundercats, but I'm just disappointed to see it fall into another "let's make this serious show into a comedy" bit. Plus I don't care for the way the creators and what little fans the show has are responding to people criticizing the show. Thundercats Roar would work if it was an online parody or a five minute commercial parody, but since it's not it's just very distasteful in watching it trying to mimic Teen Titans Go. And, dear lord, the artsyle! I use to feel bad about my art, but after seeing what the show is going to look like I don't feel half as bad.