People complained about the Prius, but plenty of people drove Mini Coopers, which looked even more ridiculous and were far less functional. You can't please everybody.

I don't even really understand the complaint. I quite like the way Rivians look.

It's a fairly generic body shape, but the headlamp and grille shape is distinctively "happy" instead of "aggressive" (this is a real thing, and it's intentionally designed for in lamp/grille shapes on cars)

Personally, I don't want "aggressive" near my cars. They kill enough people already, and I'm tired by how common it is for manufacturers to push aggressive body shapes.

Cars can be a form of signalling.

I had a coworker who sold his small lexus, because it made dating weird.