Charging an EV truck at an EV charging station? Of course that's fine.
I am probably the user the OP is talking about (misrepresenting really). The OP (in another thread) was discussing putting a level 2 adapter on his diesel powered expedition camper for powering his house electrical system. If I recall correctly he proposed to park/plug up at free level 2 chargers on cloudy days, so he could work remote on the cheap. I asked him not to do that, as abusing the privilege means some areas will just ban all RVs from using level 2 charging stations. On my new rig I will probably carry an adapter to connect to level 2 chargers in a pinch. I however will have a high powered charger, so I only need 20-45 minutes for a quick top up.
A gasoline/diesel powered RV using a public EV charging station as shore power for hours a day? That could pose an issue in areas with limited charging stations.
If you have a high powered charger for your house batteries, and just need a brief top-off that probably isn't much of an issue. But I have seen RVs parked at cheap/free level 2 EV chargers for 8+ hours. Ostensibly to avoid paying for a campsite with hook-ups.
Using a public EV charger as shore power is only really an issue for level 2 chargers, as DC fast chargers (level 3 chargers) are high voltage DC. I haven't seen anyone try to design a charger for 12-48V house battery banks using a DC fast charger (at least not yet). That would likely be prohibitively expensive.
I also find it somewhat amusing how many folks immediately start bashing on EV owners. Early on there was a decent percentage of enthusiastic advocate owners. We are long past that now, with most EV owners (like myself) simply doing it because its cheaper and easier for our usage.