Round table

a counter-question: when was someone's desire a condition for a stalemate?

In chess, a stalemate implies the inability to make a move, i.e., the scenario with gnomes and a fly is also not a stalemate in the literal sense. I think that's why the rules don't refer to a stalemate situation, but to a "stalemate," i.e., any situation in which the battle cannot be ended.

the defender owes nothing to anyone - they have to accept that they have been attacked

Well, yes, that's their difficult fate. But what does this imply?

so you are claiming that if the attacker has the opportunity to attack but doesn't want to, that's a stalemate?

I believe that if both don't want to fight, then it's a stalemate.