Honestly, that right there is a big part of why I don't do collabs with people I don't really know. When someone suggests 50/50 split, I'm thinking this person is gonna take on some of the drawing load as well or let the artist also work on the script. Hell, even if someone feels like they can't draw, you can still learn how to flat, how to do lettering, how to promote the work, etc.
It's what many of my collabs did -- we split the work. Some of us were more writers than others, and some of us were more artists than others, but we still split the load. Some of us did lineart, some of us did flats, some of us did shading, we ALL had a hand in the script, etc.
I'm not going to collab with anyone who thinks "writing the script and nothing else" is worth 50/50 when it comes to doing a comic collab. And I say this as someone who does both. Want to have 50/50 -- pitch in and do some of the flats, some of the shading, some of the lineart, let the artist have some say in the writing: then it's 50/50.