> a lot of us use our own opinions when we inevitably find a corner case that isn't working exactly the way we want.

Most standard toolkits provide escape hatches to have your custom components. I think most designers wants their view imposed to the users instead of following the platform constraints. Like instead of the standard play/pause button every player have, they want their own custom ones. Instead of using the standard tree widget, they want to create another that is the same, but behaves a bit differently. And then they say GTK is not good, let's go with HTML in Electron.