I feel like it's important to establish that "controls should look like the browser intended and not be customizable" is an ideological stance, not an obvious and self-evident truth. And it's one that I strongly disagree with, because it's needlessly controlling: why shouldn't developers me able to make something look however they want? The web is a platform for _all kinds of creations_, not just "website that look and feel like websites", and people should have the freedom to do whatever they want and not be constrained by arbitrary limitations of bad APIs.