The stocks of a lot of these SaaS companies were priced on the expectation that they could become the next IBM: become entrenched with the customer and then hike prices until their eyes bleed.

A lot of companies have been too smart for that, and a lot of SaaS offerings are too small to be truly entrenched. Arguably the investment horizon is too short (IBM took decades getting to that point).

The only real vendors who managed to become the next IBM are the cloud providers.