I think the issue with them is twofold. Presentation is hard to make look alright, and I think we do have a built in aversion to them, because evolutionarily bugs mean food that's gone bad. That said, plenty of cultures do eat bugs. It's mostly a European thing that bugs shouldn't be eaten. Places in both Africa and Asia do eat them, and I imagine other places as well. I have heard they can be tasty. Lobster was considered bad for a long time, but it's delicious when prepared properly (and butter helps).

I think another good source of animal protein are oysters. They're pretty easy to farm and they don't have a nervous system so don't feel pain. That said, most people think it's disgusting to eat raw oysters (which are even alive when eaten), but they're also delicious. It's just a culture thing. Plenty of foods that seem disgusting aren't.

I don't disagree eating plant sources is a good idea, but they do have different nutritional profiles. Animals have nutrients that we need that you won't get from almost any plant. We need diverse sources of food. I have no issue with small scale animal farming, but large scale is wasteful as hell. We grow so much corn to feed cows and other animals that could better be used for other things.

I disagree with this though:

It seems to me just an excuse to continue overpopulating the planet.

What is "overpopulate" mean? If everyone is fed and taken care of, isn't that by definition not overpopulated? Who decides what the correct amount of people is? If you're religious then certainly more people alive means whatever god(s) decided that, and if you aren't then you must know it's arbitrary. More people isn't bad, as long as it's sustainable and doesn't cause damage to the planet. That said, we are causing damage to the planet and we aren't going to stop reproducing just because someone said so. We should reduce the impact people have instead, because that's the only real choice we have. A mandate stopping reproduction is not a real choice.