It is the next best completely free alternative. Whether people like it or not.
GIMP has had literally decades of development and even with Photoshop in the worst state it's ever been in, it isn't competitive.
How is that an argument? How do you get the idea that GIMP is basically required to be competitive, just because it's old? Completely disregarding the fact it's made by volunteers vs a billion dollar company. And also completely disregarding the fact that Photoshop is even older than GIMP. By your own logic, just going by age, how can they be competitive when they are half a decade younger than PS?
Rewriting the whole thing would sure help. But not with the "I'm not going to help, fuck off" community.