Without being rude that seems very small minded, any developer who would let what some people rant about online decide what they do should really have read into running a business before hand. Linux is a very popular OS for X-Plane users, just a quick browse on X-Plane.org and you can find so many of it's users use Linux as their OS for XP. And I agree, it gives much better performance for XP than Windows, I get an easy 10fps increase on heavy planes like FF767 which is very large in size. Imagine if Microsoft said "We won't offer any hardware support for gigabyte products because someone kept ranting at us about them." That would just be dumb.
I can only hope that your mind changes in the future hopefully with XP11. As of right now I'm not a SMP or RWC user as I'm on Linux atm. Also always had a little dissapointment with SMP, never does heavy clouds or overcast conditions. Always gaps in clouds and very small amount compared to real world data, Rendering settings slider makes no difference.