My thoughts are, they are for anyone to use, and I am anyone... Over a lifetime, the cents add up to dollars. There are plenty of paid chargers all around here (Long Island NY), so if they really NEED a charge, just like everyone else they have access. There is no shortage of chargers, there is a shortage of free chargers though. This is Long Island, there really aren't a lot of apartment dwellers, so almost anyone using it, is in the same boat as me.
It's almost always a TLC/Uber/Ride share vehicle using the free charger. They have every right to use it as well, even though the electricity they are using is commercial.
Here's the thing though, there is no reason to get pissed off. When we show up to used chargers, as long as someone is actively charging, you have no idea of what their situation is. Perhaps they are about to start the first leg of a long trip and need the extra juice. I am going to assume you are talking about paid L3/L4 chargers here in the US, if that is the case, they are paying to get the juice, that is their right to be there. It is also the right of the charger company to charge idle/high volume fees. If I need to go to 100% and am willing to pay a higher fee to get there, no one should be pissed off, I'm paying for it. But the minute my charging is complete, if people are waiting, it is on me to unplug and get out the way ASAP (should be immediate).
I hate when people finish pumping (ICE)/charging and sit there in their car to set the GPS or find their favorite tunes... Get out of the spot and fiddle at the side of the road/parking lot.