You've perhaps inadvertently put your finger on the issue. This sort
of insurance covers the public at the venue, not the venue itself.

So if you burn it down, the only claim it'll pay will be from
attendees who failed to flee quickly enough. Rebuilding the hotel
afterwards is SEP.

Which policies fo you have in mind? During the brief period when I was
a "sole trader" and required to have public liability insurance (PLI) it
covered me for just that - ie burning down a customer's offices - among
other things. It was cheap as I was not wielding anything more
fire-raising than a laptop.

Looking at it another way, are you saying that if electricians were
negligent while installing new circuits in a building which leads to the
building burning down then their PLI won't cover them?
--
Robin
reply to address is (meant to be) valid