I somewhat agree with the OP, but for different reasons. I thought FFX was one of the worst FFs when I played it, and I had played all FFs from 1-10 back then. Meanwhile, I thought FFX-2 was a lot better game despite everyone hating it.
To mention a few things I greatly disliked about FFX, I thought Tidus was a horrible, whiny main character. I admit, I noticed on my 2nd playthough that he does get better near the end of the game, but it's a bit hard to like him when he's been so annoying throughout the game. This was the first FF game to have voice acting, and unfortunately, I thought the English voice actors of Tidus, Yuna and Seymour failed big-time. The battles felt like a chore to me, especially because the random encounter rate was so high sometimes, and also because I wanted to level up every character, so every battle dragged on with me recycling the characters, having 4 characters do nothing but defend, and 3 characters do the actual fighting. The latter is pretty much my own fault, though, as nobody forces me to level up all the characters.
The cutscenes felt longer than in any previous FF, and it's especially problematic when you can't skip them and they happen just before a major boss fight. It's seriously frustrating to lose to (SPOILER)Yunalesca, and then be forced to watch through the same long cutscene all over again. The addition of voice acting seemed to reduce the role of music more into ambient background music, making FFX one of the weakest soundtracks in the series, IMHO. Now that I think about it, the PS2 FF titles had arguably the weakest soundtracks in the FF series. On the other hand, FFIX and FFXIII/FFXIII-2 have some of my favorite soundtracks in the series. Finally, I thought FFX's mini-games were very disappointing. Cloisters of trials were extremely annoying, not to mention they were repeated several times in the game and as a compulsory part of the main game. Also, thunder dodging, butterfly catching, getting a perfect time for Chocobo races... yikes. At least Blitzball was enjoyable once you got used to it. As for the good things, I thought Auron and Rikku were enjoyable characters, the story is pretty epic and the ending is very beautiful and emotional.
Now for FFX-2. I thought the voice acting had improved considerably. Especially for Yuna. I also liked her character development. While her more cheerful features might be annoying to some, I liked the way how she changed from a doormat trying to please everyone to an independent character having her own free will and opinions. The story is pretty light-hearted in the beginning, but it does get darker and more emotional ever since the end of Episode 2.
Some have said that the battle system is horrible in X-2, but I didn't really think so. The battles are fast-paced and fun, and the ATB system used isn't much different from the one used in FFs 4-9. The job system wasn't bad, either. It was a bit similar to the ones used in FFIII, FFV and FF Tactics, and those FFs had really addictive battle systems, IMHO.
When it comes to cutscenes, fortunately you are allowed to skip them in X-2. I also liked how there's a save point before the final battle, and after a long cutscene, you're allowed to return to the save point, which wasn't the case in FFX. The final battle is neat in a way that (SPOILER)you'll get to beat "Tidus" (actually Shuyin) there, with Auron, Jecht and Braska cheering in the background. The scenes after the final battle and during the ending are enjoyable, even if the ending feels a bit rushed. There's also a "good" and a "perfect" ending for those who want some extra scenes.
It was interesting how FFX-2 made me care more about the world of Spira, and after playing the game, I also enjoyed FFX more than on my first playthrough.
EDIT: Just to clarify, I think FFX-2 is a great game, but it's definitely not the best FF.