One of Grin's selling points is that the underlying machinery is even simpler than Bitcoin, so I don't know that added complexity at the user interface level currently is meaningful if it is really simpler at its core. And it is certainly much much simpler machinery than Monero.
Another issue that a critic might raise about Monero (or Bitcoin) is the rapidity of its emission schedule and unfairly rewarding insiders (and this is doubly true about Monero because of its even faster emission than BTC and the issue of crippleminer, claymore, etc.).
I think there's plenty of space for something that is simpler and lighter weight than BTC, maybe almost as private as XMR, and offering a much more fair emission schedule to late comers than any other project in the whole cryptoverse.