Oh yeah, definitely. Nintendo refusing to change with the times and sticking to cartridges was a major reason for this. Just not many companies were willing to continue the old ways when there were much more financially resposnible options available.
It really hurt the N64 overall. I remember wanting only one or two games outside of what Nintendo released. Only one was an exclusive to the N64 as well.
RE: Nintendo 64 Game Development Sees Major Leap Forward with Pyrite 64