That's the whole reason why they call it like that, because they don't understand it and it seems like something magical. And it will always be like that in the current materialistic paradigm. Why would dead unconscious matter suddenly combine into something which seems to have some kind of consciousness? Also see the Hard problem of consciousness:

https://en.m.wikipedia.org/wiki/Hard_problem_of_consciousnes...

What oxygen-breathing cells do is pretty much nanoscale combustion, so the analogy seems apt.

The proton gradients are quite different from combustion though…

The proton gradient serves to regulate the combustion, one molecule at a time...