But then companies that make their money by upselling to SaaS really don't like it when Amazon comes along, takes the software, and undercuts them in the cloud.

But then companies that make their money by upselling to SaaS really don't like it when Amazon comes along, takes the software, and undercuts them in the cloud. The company then scrambles to change their license to disallow that. Wolfram in that sense is just being honest about their motivations by having it be proprietary from the get-go.