Discriminates against windows users??
Xara were VERY open about the opensource project. They make money on Xara Xtreeme. It's their bread and butter. They wanted to provide products on OSX and Linux but didn't have the time or the resources to make it happen. They started an Project providing code to devs to assist, and making the results freely available.
As I understand it the lack of take up stalled the project. and while this is a pity you can't expect a small business to give up its revenue stream just because it doesn't suit you.
they tried they failed they moved on.
Xara Xtreeme is a brilliant produce at a great price for windows users. I would have loved it to have been the same cross platform but regardless I have no issues with Xara.
I really think you are confusing discrimination with economics. It was not economic for them to develop on their own the linux version, it wasn't them discriminating.
For those who want to check out the project :- www.xaralx.org