This sort of reductionism of the scientific method does down your own discipline.
No it doesn't - of course our methods have become much more sophisticate over time, but the basic concepts of systematic experimentation and repeatability have been there all along.
And if working out how to make fire is the scientific method
When it involves a systematic trial and error approach that leads to a repeatable method to be able to start a fire in a manner which has utility, then yup that's the scientific method.
, then thinking fire is a good thing to have is philosophy.
See what you did there NS - you've expanded epistemology to be all of philosophy, when it is, of course merely a small branch of philosophy. Sure the early humans may have considered fire to be a good thing, although I'm not sure even then that would represent philosophy (which requires study, rather than just an opinion on something), but I doubt very much they'd have been sitting around enjoying their fire and debating the nature of knowledge.
Again none of what you are discussing here is science. You are talking about science philosophically.
Nope, wrong again - we are discussing whether early humans used an early form of the scientific method to innovate, e.g. to create fire, tools, pigments, agriculture. And sure they did - they were early scientists.