I mean, it's safe to assume that most of the "Bitcoin is a waste of energy" people probably didn't even spend enough time thinking to grasp the concept of "store of energy". That, along with the dozens and dozens of nonsense criticisms against Bitcoin.

As far as I know though, the argument against Bitcoin's energy usage is mostly in the environmental perspective. That Bitcoin is unnecessary hence is causing unnecessary damage to the environment. Funnily enough, people criticize Bitcoin's energy usage with them turning a blind eye on other "unnecessary"(not necessarily bad, but not necessarily needed for humanity to survive) energy hogs such as Christmas lights and gaming consoles.