Bullshit. I was there during the '90s too. SunOS was the cool kids' UNIX at the time and you could get retired 3/xx series Sun hardware cheap. Linux did run on a common PC but was a bug-ridden, totally insecure crock of shit until about 2.0.
Well I was there too, and my recollection is a bit different. First you couldn't get "cheap" 3/xx hardware unless you were lucky or connected, and second Linux may not have been performant early on, but it wasn't especially buggy or "insecure crock of shit", well at least not compared to anything else. SunOS came with a boat load of severe vulnerabilities right out of the box for basically the whole of the nineties. And it was neither worse nor better than anything else. Security just wasn't understood or on everybody's radar until it started to pick up the very last years of the nineties.