People usually don't to art for just the money, but often times money is a requirement, especially if the artist does art for their lively hood. Art takes time and time is something that people just don't have a lot of, especially if they also have a job. If an artist can get money for their artwork, it is a motivator to spend more time on art. It can assure them they can be in sound financial standing while also doing something they love, and that's something everyone strives for. Plus, it's a little unfair to ask for any kind of service and wanting it to be free.
I hope this doesn't come off as rude, and I'm short on time right now so I'm not sure if I explained myself well, but I hope you can understand this from the artists point of view. Money is a motivator for live, it doesn't have to be sad, it's just a fact. And that's something no creator should need to feel guilty about.
In any case, I hope you find someone you can collaborate with. Another option would be to simply write your story and then look into an illustrator afterwards. I've seen plenty of novels get a comic version after they've been written.