It's hard to say. I suspect the more "hardcore" fans liked it better, since they were able to get past some of the more frustrating aspects of the game that less-skilled players would have perceived as obstacles to their enjoyment, such as the camera controls. Veterans of the series and people who'd previously reached the SM64 skill ceiling (relatively speaking) wouldn't have had as many issues, but its shortcomings are undeniable; the camera controls first and foremost again, which make much of the trickier platforming sections hell, with hard-to-predict jumps and objects obstructing the view in more closed areas. There are some very punishing situations where you have to restart challenges from the very beginning without any sort of checkpointing if you don't do well (the casino secret star, for example, which has a long setup sequence just to enter the actual level). Some ideas feel halfbaked, like the rollercoaster with the terrible missile controls and lack of aim, or the pachinko level with weird awful physics that push you towards the center for some weird reason. There are a ton of "timeout situations" in the game - having to collect blue coins before a timer runs out, having to wait for platforms to align, Yoshi running out of juice, etc. Some of the hotel's and other shines were somewhat obscure and hard to figure out without it actually being fun.
The FLUDD gimmick was also very love-or-hate from what I've seen, although I personally was fine with it. Aiming FLUDD was a pain sometimes though, specially while moving, which they expected you to do both during levels and the "chase fake Mario" sequences.
All of those are things I see stopping "newbie" players dead on their tracks, but longtime fans would have no problems dealing with.
