It's `curl foo | sudo bash` that's the bigger objection. Running software usually shouldn't require root, and then the equivalence argument you make doesn't hold.
Concern over "sudo" requirements is always fair but it' nothing to do with curl+bash over how else you download and ran it.
Installing from distribution package is much safer than curl+bash because it doesn't require you to extend trust to anybody else. You could argue that malicious code could still pass through the distribution mechanism, but at least it's fully auditable and you're guaranteed to be in the same boat as everyone else.