I also think it helps to appreciate the historical context: this game was a major milestone in the development of the 3D platformer genre. Some of the bugs or treacherous optimizations may look naive to us now, but there had been few if any opportunities to make those mistakes prior to Super Mario 64. And in spite of the glitches, the game managed to be a huge success and highly influential even outside the platformer genre.

This video does a wonderful job of illustrating how a handful of underlying issues can combine and manifest in so many different ways, and this was only the tip of the iceberg of 3D game physics glitches. And some of these issues are things games can still fall prey to today.