Off-color fetches mostly just bother me because it looks like someone's being wasteful with money.
The alara shard lands I'm guilty of running because they're essentially really cheap dual lands. I'd feel bad about it except nah I don't really care to spend $$$ per card slot to upgrade them to on-theme lands which would be functionally better in every way.
Otherwise there's so many other things that could annoy me so much more in a game of commander than off-type fetch lands. For instance, I'm still mad about that one time somebody played humility
in one game like a year ago.
I like the restriction on hybrid cards, personally, because it limits more what cards can be played in a deck, and for some reason I find "good staples to put in every deck" the most offensive of card types. Trying to find a general with a large enough color identity to run whatever hybrids you want just seems like a part of the game to me.
Also, "is there an off-color mana symbol not in the flavor text" is a really easy rule to remember for deck construction.
--edit: This is slightly bothering me. You can play fetchlands with no basic land type and no mana symbol in any deck, they just tend to not work well. Naya panorama
works for colorless generals, for instance. Unless I'm confused here.