"Chase dislikes Mono for a variety of reasons. "A sketchy patent cloud hangs over it, and I prefer to keep on the level (my music collection is mostly ripped to OGG instead of MP3; I prefer to browse without proprietary extensions; etc)," he told iTWire.
Additionally, "it's a bit bloated for my poor low-end machines - both in terms of disk-space and the runtime memory footprint and I find C# (the first-class language of Mono) an ugly and hackish language.""