I think that it's a difficult situation. If the artist wants to pay the writer then they should certainly do so. I find it very uncommon regarding that circumstance, but it is ultimately up to them.
After lots of reflection, I see that everyone should be paid for their work writing or drawing. When it comes to collaboration it gets tricky because people then ask, well is one more important than the other? Should one be paid?
I guess that's why collaborations exist, as they live as equals, not separations. However, some people realize that they need others and are willing willing pay which is their own choice. Overall, it's sticky.
I guess it comes down to this, all artists (writers and drawing as artists) work hard on their crafts and should be paid. When it comes to collaborations, a deal is formed where they become a team, working together.
Do writers deserve to be paid? Yes. It comes down to situation and ultimately the individuals involved.
I also want to apologize to any I offended. After looking at all the feedback, I realize my error in my comments and I've looked at it from a different point of view. If you are able to, please accept my apology with time.