I agree with you. The only reason almost all of my stories have their own custom layout is because I enjoy making them. But it's not the most important thing in a story. I don't care if the story has a very pretty layout. If it's badly written, I won't even hesitate to click the back button. There are a few of my favorite stories that use mibba default layout and I enjoy it very much because it's easier to read than most of the layouts you can find here and it's written brilliantly.