By using Fedora, one helps Red Hat/IBM in different ways:

• With more usage of Fedora, Linux enthusiasts cater to that distro more and more, and Red hat benefits from all that feedback and large customer base. Fedora gets better and Red Hat stands out over the competition.
• With larger customer base, Red Hat's board approve to allocate more resources to the platform, increasing its competitive advantage.
• With more users of Fedora, Red Hat can find more qualified professionals that grew up using already Fedora, increasing its human capital competitive advantage.

Customer base, paying or no, is a tremendous competitive advantage... that is why Microsoft winked at piracy across the globe for 2 decades so companies purchased their solutions since millions of users already knew how to use them. Of course, once the competition was out, Microsoft started to hike prices tremendously.

Of course, the development of Fedora, since it is FOSS, benefits all the community, but it also feeds the monster in the process that, at the moment they want, they pull the rug on the community that, at that stage, won't have any companies that can take the lead anymore.

The moral here, if behind Fedora is a company that did bad things for FOSS, that it is owned by a company that contributes with the IDF, and both are based in a country that any day may ban Red hat technology to be distributed to any foreign country of their choosing... why choosing Fedora when plenty of alternatives are equally comparable, more ethical and less prone to manipulation.