Maintaining software on Linux just takes more time and effort - due to less stability and number of distros.
AMD is making more than enough money from hardware sales to fund the software that actually makes is usable.
Even Apple doesn't charge you for the software needed to actually be able to use their devices (well since around Snow Leopard or so, at least).
But I suppose the idea of not being as greedy as possible really "pisses off" AMD's executives (and presumably some of the people shilling for them here).
And presumably you didn't read the article since AMD will continue to support this on Linux anyway.
AMD does maintain Linux anyway, for their paid tiers. It's not like they're saving money by dumping the free tier for Linux.