Complete bollocks.
First point: a planet would not have to be similar to Earth to necessarily support life. All it would need is conditions able to support the organic proteins that gave rise to life in the first place. When life first appeared on Earth, the planet was more akin to Venus than the Earth we know today. It had an unbreathable atmosphere, nothing but rocky outcrops and oceans, and the entire planet was entirely covered in violent storms.
The Earth that gave birth to life is fundamentally different from the Earth today that now sustains it. If a young, violent, inhospitable Earth was able to host first proteins, then bacteria and simple celled organisms, who is to say that other seemingly inhospitable planets aren't also able to do so?
Second point: the fact that humans are the dominant species on the planet is a complete fluke. We are simply a species that were lucky enough to fill a particular void left during a certain era in history. If the dinosaurs hadn't been wiped out by a meteor, then it's a fair guess to say that the dominant intelligent life-form on Earth today would be a reptilian descendent of the dinosaurs, probably complete with tail, scales and double jointed legs. And if not the dinosaurs, one of any of the millions of other species on this planet could have arisen at any point to become to dominant species.
The fact that humans inherited the Earth does not suggest that our form or functionality are in any way superior to all other life. In many ways, we're incredibly deficient. Our senses are pretty poor compared to other animals, our bipedal nature means we have a very limited running speed when contrasted to the dominant land predators, we're almost completely helpless in water, and we generally lack the musculature and strength to adequately defend ourselves against predators without the use of tools. When compared to our closest primate cousins, we come off as an incredibly weak species. The only thing our biological form has in its favour over other life-forms is the ability to use fingers and thumbs to grasp and manipulate objects, and a brain large enough to process and retain a lot of information.
Human dominance of the planet only serves to show the random, unpredictable nature of evolution at work. At any point in our early history, we could have been wiped out by a natural disaster, hunted to extinction by predators, killed by our own violent nature... the only fact worth taking away from our early history is that we were a species who happened to be at the right place at the right time to be able to survive and thrive.
What does this have to do with aliens? It shows that there is absolutely nothing that we should expect space-faring aliens to have in common with us, except the ability to somehow manipulate objects to create tools, and some form of brain that allows them to process information. To assume anything more than that is simply an act of narcissism. We got lucky. Even if there are humanoids of any kind on other planets, who's to say they got as lucky as us? We may explore the universe, only to find that the only comparable humanoids went extinct on their homeworld millenia ago.
