My wife bakes bread almost every day and grows her own yeast. She loves it and the bread is fantastic. What is so ridiculous?
There's a lot that's ridiculous about bread being so expensive that recreating the entire supply chain in your backyard is the only economically viable option for obtaining it.
The metaphor pretty clearly was not about critiquing baking as a hobby.
Insulin must make it into the bloodstream intact, typically through injection. It’s also incredibly potent, a unit of insulin dried to crystalline form weighs less than 40 micrograms, so it much be administered in a sterile carrier fluid.
Lastly the penalty for overdosing is generally called insulin shock or diabetic hypoglycemia, and ‘it is rare but possible for diabetic hypoglycemia to result in brain damage or death. Indeed, an estimated 2–4% of deaths of people with type 1 diabetes mellitus have been attributed to hypoglycemia.‘ [1]
That’s with pharmaceutical insulin, not DIY.
In addition to doing it the way you described (put out flour and water in a bowl and wait for it to bubble and smell nice), you can also buy a $100 microscope, collect wild yeast, clean the bactiera off, and grow mass cultures. Sometimes it pays to work at the last step of the industrial, scientific and agricultural revolutions.
Regardless, it was all still done with science: Observation followed by trial and error informed by those observations. Maybe not the scientific method formalized by Francis Bacon, but it's still there in the outlines.
Either way, I don't see a fundamental aspect of the scientific method missing from an observation -> trial -> results loop. I also don't see crop cultivation as unintentional, although I'm not clear what you meant by that. What wasn't intentional? Deciding to experiment with planting seeds would have been a deliberate choice. Probably based on some observation that where wild grains were gathered together and and little things fell off of them, sometimes the same type of plant would grow. Followed by the idea that putting those things in different places might produce the same effect. Etc.
I don't think you get from wild gathering in a nomadic lifestyle to settled agriculture without observing, coming up with ideas about what you observed, testing those ideas, and checking the results. That is. A scientific process.
Toesinte turning into maize would may have simply been a blind generations long domestication process, but not that spark of insight and experimentation that led to stationary agricultural societies.