The impression I got over the years is that perhaps de Icaza was actually less interested in the Linux desktop and more interested in language technology, start

The impression I got over the years is that perhaps de Icaza was actually less interested in the Linux desktop and more interested in language technology, starting with CORBA, and then when Microsoft released C#/.NET, he shifted to that and started Mono. I guess what I'm trying to say is that you probably really can't blame Microsoft.