Some version of SCO had already made a hash of a multi-vendor datacenter Unix. Before Linux became commercially popular there was a lot of interest in 2nd and 3rd tier vendors in an enterprise Unix that would have enough marketshare to interest ISVs. But the project pretty much flopped.

Linux didn't really have a big effect on SCO until they were already flailing. It was mostly Windows NT that was eating their lunch. SCO tried to claim that it was Linux that caused them to go downhill but the timeframes just don't line up. Source: I spent a lot of time studying this at the time.