Yeah, as much as we sometimes wish for something to happen right now, Ansar Allah just inviting an all-out war doesn't give them any direct benefit. It's not going to stop the genocide of Gaza tomorrow.
Or at least there is no extra benefit to shooting every ship in range as opposed to small-scale attacks consistently enough to disrupt shipping in the area and place stress on Western economies. They know for sure that they can withstand another bombing campaign better than the West can withstand losing their treats.
I'd guess this is a corruption thing and not offical policy. Not paying your mercenaries when you're already having manpower issues seems like a bad idea.