I don't think it is possible to get into this without questioning why we do or don't, at least among ourselves.
I do. My snakes are simple, dumb, basic creatures with limited (no) ability to appreciate or enjoy things like environmental enrichment. Being able to get a drink or stick their heads in water or soak if they so chose is one of the very basic things they CAN do. And frankly I'm not interested, personally, in doing the bare minimum that they can survive. I'm not going to start deciding to take them on walks or deciding they love me, but a bowl of water and a hide? Yeah. I'm giving them that, because those are the little things they can and do make use of.
They're simple, primitive, animals but they're still ANIMALS. I wouldn't keep a FISH without a plant or something to use a hide if it so chose (though admittedly dark tubs in racks BECOME hides, so that's not an issue in those scenarios, it is for mine as they're in clear containers without racks).