Though I agree the use of humanoids in science fiction reveals a bias towards humanoids, I find one flaw with your argument. 20 years ago, astronomers would have said our solar system is the primary form, and we won't find stable deviations, and yet every system found has broke their models. Trappist D is just one example. Jupiter size planets can be next to the host. We can have binary stars and double Star Wars-esque sunsets. Even triple sunsets. Your sample size for how nature will respond to evolving life on other planets is presently limited to one, which is insufficient to extrapolate that there will be no other humanoids. Why wouldn't nature recapitulate what clearly works? Will there be other forms? Absolutely. The diversity on Earth alone, through its entirety, demands there be other pathways. The Octopus candidate has been growing in esteem. Saying we will never find aliens that look like us is just as absurd as saying there is no life out there at all.