Why not? Its not an open standard. This is the rent-seeking behavior you get under for-profit capitalist implementations. This is why we push so hard for open standards.
Also a non-profit is just that, its not a charity. A charity is an entirely other classification and even those are regularly used and abused like this.
Non-profit is a business arrangement where making money isn't the goal. There are many different versions of one though: many local clubs are a non-profit and they exist only for the benefit of their members.
Nobody cares if the mailing list where they discuss the upcoming specs is managed by a non-profit, the broader HDMI ecosystem is still a massive money grab.