The guy sounds like an a-hole. To answer your earlier question, no, I wouldn't much want to support a universally hated owner. Sounds a lot like Bud Adams who was very much hated in Houston before, during, and after he moved the Oilers to Tennessee.
Anyway, no, there was no need for any external "pressure" on the Austin City Council to kill the downtown waterfront site. It's officially designated at "city parkland" which is an immediate hot button for all of the greenspace advocates around town. You can think of Austin as being very similar to Portland, or Berkeley, politically. So there was pretty much zero chance any publicly owned parkland was ever going to be allowed to be developed for such a venture, and ESPECIALLY not anything that is right downtown at the epicenter of the "save our greenspace" political interests.