Convergent evolution is a thing. Aliens that live in similar natural habitats and that fill similar ecological niches as humans will likely evolve along similar lines due to facing similar pressures. With that said, this is a very big assumption and all that it really tells us is that it is not impossible for “humanoid” alien life to exist.
Also, whatever is out there, we’ll never know for certain. Distances are just too large. Space is so incredibly, unfathomably big that it’s almost certain that there’s other intelligent life out there. However, space is also so incredibly, unfathomably big that it’s almost certain that we’ll never meet it.
Considering that OP’s teachers apparently beat their students (or at least stand idly by while their colleagues do), I’d argue that they do not deserve one ounce of respect.