I don't think there's really anyone who would turn away the opportunity to have their work animated. It's a lot more mainstream and has a broader appeal so your story would reach a lot more people. I'd say most creators here use comics as the medium to tell their story over animation since it's infeasible to animate it themselves, not because they don't want it.
Of course there are those who just prefer the comic format, but even then nothing's stopping you from continuing your comic as the anime airs (unless of course that's a stipulation in your contract).
