Similar routine here. I attribute the long priming time to the distance gasoline must travel from the gas tank to generator carb. I think over time the gasoline slowly drains out of the fuel line back into the tank, and you have to pump it back up to the generator.
I concede this may very well be true, because my fuel tank is very close to the genny. At least my use case supports your theorem.
It would be very tough for me to buy another RV, I would not be worth the trouble for a Dealer, because I will want all of the things I have now as par for the course. But who knows, my next coach may not even have or need a genny? Solar may built in on the outside rear and side walls and maybe small enough to mount on AC cover panels (not the roof).