So far as I am aware, ALL usable operating systems are burdened with that sort of thing. I'd really like to see someone at least attempt a clean-slate OS. Make it 64-bit only from the start, vector fonts to support HighDPI displays from the beginning, etc. It would likely accumulate such cruft over time, but I would expect there to be substantial advantages to building from scratch something that rolls in all of the research advances and assumes capable modern hardware.