Some people don't see electric cars / chargers as ideology that must remain absolutely pure of oil. Some are just pragmatic - it's a good car that runs cheaply, and supercharger is critical infrastructure that needs a reliable backup.
It’s normally the anti-EV people that seem to go for this angle as a kind of “gotcha”. They are normally the ones spreading the “all the chargers run on diesel generators” misinformation too.
Can you run a charger on a generator? Probably. Is it standard practice or mildly common? Absolutely not.
> Tesla uses local diesel generators to handle spikes.
This suggests that it is a standard solution for a reasonably common problem for Tesla. Common enough that it is seen as the accepted solution by the company.
The only instance I have ever seen of this was an attempt as anti-EV misinformation which was debunked. It is not a common solution at all.
It would definitely be a viable solution in some places and I am not against it, but for some reason the anti-EV lot want to push a narrative that it is common when it is not.