Well, doing philosophy is part of my day job. Which may be part of why I'm not a big fan of Planescape's take on it.
See, I'm completely the opposite. Dead Gods makes me yawn - as written it's one of the most railroady modules I've ever seen. Whereas the 4e cosmology just keeps giving and giving with game-driving themes and conflicts.
Oh, heh, Dead Gods was pretty bad in that regard. But I think that's less a judgement on Planescape as a setting than adventure design issues that, if I recall, a lot of TSR adventures possessed.
Don't get me wrong, I'm actually glad 4e created a new cosmology. What bothered me was the designers claimed to have seen the light and realized that ALL of us had been doing it wrong.
I think everyone is going to have different takes, and 4e provides new ideas and new options. Not everyone is going to like it, just like not everyone is going to like Planescape. For me reading the primordial vs gods, and seeing the elementals with helmets and faceless angels...made me stifle groans of embarrassment for the 4e cosmology.
I do like that the Feywild and Shadowfell border the planes, we'd already seen this stuff elsewhere so it wasn't a great creative triumph but nice to put it as a central feature.
Oh, and someone mentioned preferring Shadowfell's Keepers to the dabus? Er, the Keepers are at least as old as Planescape.
As for the PS backgrounds that no one sees - I think that is group dependent. I remember hearing one amazing story about how players called in their favors and political connections and stopped Faction War before it started. Shemmy's characters (and thus her players), from her excellent story hour, live their backgrounds and almost all of them had planar origins or acclimated well to planar life.
But yeah, we're just tossing opinions. Everyone is going to love different RPGs. I know people who were in love with Kult, but having read the sourcebooks I find it way to over the top horror to scare me. Some people hate Mage Awakening, as did I, but over time I've grown to see it as a worthy successor to Ascension.
Curious, though, if you had to make a faction based on your ideas of what philosophy is, what would its beliefs be?
Edit: Just want to say I am not attacking your game, or saying that your conflicts are boring. I actually think they are really cool and interesting, and...heh...would be served better by the Great Wheel. Again, one man's opinion!