As someone who loathes hyper-competitiveness, I can't really bring myself to enjoy this anime. I honestly did want to like Uma Musume, but I just can't do it. The artstyle, the animation, the music, the voice acting, the character designs, they all range from good to great, and some parts in the anime remain enjoyable enough to watch despite everything else.
However, when the entire premise of the anime (and almost everything around it) revolves around competition and the need to win and not much else, I just lose interest in it. For the most part, it doesn't even seem like there's much reason behind their obsessive need to win and compete except the boring 'I'm gonna be the best.' Even the friendships in Uma Musume revolve almost entirely around competition and rivalry. Oh they'll say 'I wanna make others happy,' but at the end of the day it all still comes back down to needing to run and win races in order to do it. Why can't it be about them having fun first and foremost, perhaps even outside of racing? Why does everybody usually treat eachother, friends or not, like rivals to be defeated? Why does every character, in nearly every scene, have this pervasive need to improve their running like it's a life-or-death situation? I would've liked Uma Musume so much more if the characters had more to their lives and personalities than just constant training/racing. If it had some more lighthearted slice-of-life moments to flesh out its characters and alleviate that serious/intense tone around its racing.
On top of that, other criticisms I have with Uma Musume is that the pacing could've been better, and that there are a few too many characters overall. This results in many of those characters being unable to really have enough screen time and character development - at least within just 13 episodes. Thus, I find it a bit hard to really care much for most of them.
To be sure, Uma Musume is definitely not awful, because it certainly does have good aspects and ideas, and it deserves a few points for that at the least. However, overall, I still didn't enjoy it that much, and that's why I ultimately gave it this score.