Yeah, Um, that would be No.
You'll have to forgive me for being biased, seeing as the first D&D book I ever touched was the Planescape Monstrous Compendium Appendix II. Nevertheless, the planes rock. (WARNING: the following post may contain far too much blather from my Ancient Philosophy class.)
Firstly, you have to have the right perspective to appreciate them. They're an infinite worlds thing. If you've got a campaign that's heavily into one tiny area and its peoples, then just ignore them.
Secondly, the Planes require just... a sort of appreciation of the nature of the Infinite. The Planes are, for the love of all that's shiny and distracting, not just "the abodes of the gods". Each Plane is described as infinite. The D&D Gods, while divine, are most definitely not infinite. You can shovel Bahamut, Heironeous (sp, stupid vowel-filled gods), the Celestial Hebdomad, Moradin, and every other god on Mount Celestia off to the side and still have a vast campaign world available to you. The Planes provide anything, with viable explanations as well. I'll admit a one-world campaign is capable of having the PCs go from a city ruled by holy paladins to a demi-nation of pure and despicable evil where the mad exert their power and the weak are fodder, but it ain't easy.
The appeal to me of the Planes is the Infinity itself. Even if there aren't infinite outer planar creatures except Tanar'ri (long story, subject for another thread), there's still hundreds of conflicts that have been waged for milennia, not to mention the all-encompassing (on the Lower Planes anyway) Blood War. You can thrust your party in between vast powers capable of smiting them easily, and then let them deal with whatever they can. You can develop intrigues in which Baatezu expatriots and fallen Asuras manipulate a druidic cult on the Outlands into rampaging across the encamped army of Yugoloths in Gehenna.
None of these themes are any different from those that you see in other campaigns or in the real world (World Wars, anyone?), but the Planes let you make the parties and locations involved truly Epic and amazing.
And I think probably the best part of the Planes is having little first level grunts figuring out stuff and dodging the millions of fatal obstacles out there, not just going with the 2e pre-Planescape "The Planes are a vacation spot for Elminster and Mordenkainen" idea.
Footnote: the Elemental/Para-Elemental/Quasi-Elemental/Energy Planes have gotten nowhere near the respect they deserve. Anyone interested in getting some really unique and exciting ideas about said locations, check out the theories on alternate natures of existance at mimir.net. (If it's still around... been ages since I checked the site.)
Also, "hating" an entire setting and vast conceptualized reality is really stupid and childish. Unless it's FR. In which case it's fine. Toril sucks. (FR lovers feel free to bash, I don't check the forums much anyway. Just FYI (OFF TOPIC, anyone who only cares about snarling about the Planes... well, you've probably already stopped reading), my beef with FR is that it has epic powered characters much like the Planes, but their world has none of the parallels - instead of incredible heroes in the midst of immesurable demon armies, you end up with level 800 Elminster sitting around in his tower while an army he could destroy with a finger slaughters loads of innocents. Also the Mandatory Divine Worship is bull.)
Rant completed. Planescape rules!