I only watched this from the outside, but my impression was that it was an overreaction. Sun had a nice research operating system based on Java called SpringOS, but when clients heard about that they revolted. The transition from SunOS to Solaris had been traumatic and they threatened to jump ship if there would be any more changes ahead.

Sun's reaction was to adopt "only Sparc, only Solaris, only Java forever and ever" as their roadmap, publicly killing SpringOS, Tcl, Self (programming language) and so on. That did make the clients happy.