Yeah, people complained about that, too. You guys are 21 years too late to be saying 'Well no-one complains about Aliens'.
Queen moulting can work. There, I said it. But the Bros didn't put enough thought into it.
Look at it like this. Sure, a drone can stick a host to a wall and turn it into an egg ... but what if there are no hosts? What if the only thing around is the one it came out of, and what if it has to eat it? Then it's screwed. But wait, it can turn into a Queen, poop out eggs, and die of old age waiting for something to come along and get hugged.
Except in AvP Requiem, there are hosts. Lots of them, in fact.
In terrestrial zoology there are organisms with three reproductive methods, except they all respond to different stimuli. If A, go to method 1; if B, go to method 2, etc. Here, we have two methods - Moulting and morphing - which respond to exactly the same stimulus - No Queen - in exactly the same circumstances - the presence of hosts. And there's your problem.