I have a hard time seeing how "gross" could describe the look of Material UI. Uninspired or unnatractive maybe, but gross? Also, it's dead-easy to customise -

I have a hard time seeing how "gross" could describe the look of Material UI. Uninspired or unnatractive maybe, but gross? Also, it's dead-easy to customise - there are a bunch of facilities for doing so, from global to component level, with CSS-in-JS or CSS class overrides. You can make it unrecognizable without that much work.