I admit I've only read a bit at the start. But I already see an argument that I hear a lot that really bugs me, about aliens being the "simplest explanation".

Thus drives me nuts.Aliens have NO explanatory power! All the weird stuff we see still has to be physically possible, and have been discovered and put into practice by someone. How the hell does adding aliens to that simplify anything?

It's possible, or it's possible plus aliens. Which is simpler?