Naaah, shit gets super-handwavey whenever science is used to justify religion, spirituality, mysticism or anything else that scientific evidence is lacking for. The object is not to make a scientific argument, the object is to make a science-ey argument.

It's pretty much the core problem of faith: as soon as you attempt to use reason and logic to prove faith, you discover that the whole point of faith is that it can't be proven. And as soon as you attempt to use faith to reinforce reason and logic, you discover that ungrounded assumptions are toxic to scientific thought.

As a species we have a nasty tendency to crave a unifying theory of everything and those annoying shitfucks that insist that if there is a god, he's hidden himself pretty well in the equations but if there isn't a god, an absence of evidence isn't evidence of absence mostly just piss off both sides. Meanwhile, those that are on shaky spiritual ground will often assemble a cosmology out of available parts - I worked with a guy once who decided he believed in Christianity simply because there's more documentation of Christian miracles on Youtube than there is for Islam or Judaism.

The transhumanists tend to be those who have a faith in "science" but it's in air quotes because they tend not to be scientists - or if they are, they tend to have expertise in something other than machine learning, bioengineering or anything else that might come in handy. This allows them to view the "singularity" as the inevitable culmination of scientific progress rather than the literal invention of god.

You probably don't want to watch What the Bleep do we know.