I think the reason why some players are a little miffed by these Paragon level is the fact that without an attributes/skill point system, it's still a somewhat static experience where you don't actually out-level the mobs like you did in the previous titles.
In Diablo 2, you could continue to pump points and build your character tree until level 99 whereas Diablo 3 will throw about one items worth of stat points when you hit level 100 and provide no change to your skills. You're essentially working towards a slightly more overpowered version of yourself which boils down to taking one or two more hits from Inferno Act 3+ mobs. Even if you're Paragon level 100, there is very little significance within those 100 levels because a) stat points per level suck in D3 and b) they still out level you. The GF/MF is another thing altogether.
If they just threw in 39 more actual levels rather than keep the cap and have alternate levels with tweaking the stats per level, it would provide an entirely different flow which would be comparable to that of D2 but that would probably break something.