Metro UI started to look good once they allowed fully transparent tiles without those horrible predefined solid-color boxes, i.e. you could select a background image and it was then tiled to launchers:

https://news-cdn.softpedia.com/images/news2/Windows-Phone-Ap...

If they had that from the day one, it could have ended up with a lot less resistance (just the ugliness of the default palette was unbearable; they must have hired an expert for achieving the most negative impression with those original tiles/colors).