Bad workers?!? Umm... whatever. (In light of the recent election, I think we've all had enough of crusty, opinionated bigots by now ; )
The topic in question is 3D platform games. Here we go...
Mario 64 was Nintendo's first shot at making a game in a completely new environment, with completely new tools, for a completely new system, et cetera et cetera.
This experience can be easily likened to the development of the original Mario Bros. You remember, the one where an endless stream of koopas waddled out of pipes and there was only one screen of action? Same thing. At the time, the home console was a fairly new industry. Those guys were pioneers in their field.
Admittedly, the guys at Nintendo had more experience under the belt in production of Mario 64 than they did for the original. However, the inexperience in an essentially new medium and the addition of another dimension (those things are pretty hard to come by, BTW) make development for the 64 extremely difficult for new designers.
In short, to compare the classic side-scrollers with the more recent 3D platformers is like comparing Pine-sol and Dran-o, or something...