[bugs]

Matlab and Mathematica seem to do pretty well at installing universally (though 64bit can cause some issues).

I think the real reason is there isn't much benefit for making software for linux when the paying userbase for windows or even mac is so much higher. This is why you really only see educational and/or research based software on linux; hopefully if linux starts to get really big we will see this change.

[Periodic]

When I first started having to support Matlab for a group I was surprised to see how well supported it was on Windows, Linux, and OS X. All of them are able to install using a total of two DVDs and they all can connect to the common license server. There are some annoyances, but they're present on all platforms.

The numerical simulation and engineering crowd have been using non-Windows systems for a while. These people started by running their programs on mainframes, but as computing got cheaper they started putting those systems under their desks, but they still ran UNIX.

As such, I agree that it's likely just a question of how big the market is and how technical that market is.