My opinion of Baby Park differs depending on the game.
I dislke it in Double Dash because it's a bit too chaotic, though I understand that that's why people like it. The music is also obnoxiously childish and one of my least favorite soundtracks in the Mario series.
It's not great in DS either...
The CTGP version in Mario Kart Wii is fine if only because of Item Rain and the fact that I have my custom music playing here. Here I've replaced the music with
Keep It Steady from Mario Party 10, and let me tell you, it's way better than listening to Baby Park's original music.
MP10 bias aside though, don't you think that Keep It Steady is a good fit for this track???
I like the Mario Kart 8 version. It has the right amount of chaos and is just more fun to race on than the past versions. Aesthetically, this version is also amazing to look at all the rides in the background. Kind of makes me wish this was a level in a 3D Mario game that you could explore...
Also in the Wii U version I replaced the music with Keep It Steady, and it's fun hearing that song getting pitched up and speedier with every lap...
I also don't mind Baby Park in Mario Kart Tour either, although I'm not a fan of the Trick version. Just that variant though, the other three are fine.
Oh, and I of course like the pink gold Baby Peach statue in the newer versions. (No it's not baby pink gold Peach)
As for what the worst Mario Kart track actually is, well, I don't think that any of the official tracks are. The worst Mario Kart track ever is probably some poorly made CTGP track, like early versions of Desert Mushroom Ruins or Mr. Bean5000vr's Mushroom Peaks. I'm not sorry Mr. Bean...