That's probably because scientists don't believe that what you suggest is possible. Scientists actually believe that humans arose from genetic modification of previously existing organisms
Manipulating genes to make something 'new' isn't new at all.
Actually if you manipulate the genes to such an extent that the new organism can't reproduce with the old one, then by definition, you have produced a new species. To suggest otherwise is simply begging the question of whether or not the formation of new species is possible. How else would you propose forming new species? If you're not going to count a genetically modified organism as a new species, then you have simply assumed at the outset that evolution is impossible rather than considering the evidence and concluding from the evidence that evolution is impossible. That might fly in religion, but never in science.
so? I'm not convinced enough to believe it but thanks anyway.