I absolutely agree with everything you said. I still find it to be a valid accounting of their own internal observations; the fact that it is subjective and not subject to external validation doesn't mean it is useless, it just means you're not extracting particular results from it that you apparently desire.
There are ways of knowing things that cannot be externally validated. That doesn't mean you can't study them within the four corners of the scientific method; we study pain, depression and lots of other things that take place in the head, too, and a big part of the input is "feelings".
But even without scientific rigor, we can know things. I don't need a study to know when to eat, and I know I've undergone perceptual shifts for various reasons. Since I'm not leading a policy crusade for legalization, a PR campaign to change public perception of legalization or a company that just really wants to sell mushrooms, I don't need more certainty.
TL;DR: there are different ways of knowing things that are good for different purposes.
There are ways of knowing things that cannot be externally validated. That doesn't mean you can't study them within the four corners of the scientific method; we study pain, depression and lots of other things that take place in the head, too, and a big part of the input is "feelings".
But even without scientific rigor, we can know things. I don't need a study to know when to eat, and I know I've undergone perceptual shifts for various reasons. Since I'm not leading a policy crusade for legalization, a PR campaign to change public perception of legalization or a company that just really wants to sell mushrooms, I don't need more certainty.
TL;DR: there are different ways of knowing things that are good for different purposes.