Hydro shop owners aren't often straight businessmen like my guy. They are season vets at this which means they tend to they have grown Photos, and whilst tons of that knowledge is transferable, a fair bit of it isn't. Autos are a niche within a much wider subject pool. Also their age old experience tends to mean they are stuck In their ways. Using techniques that they are refusing to change and believe their methods to be the best - no questions asked. "I've been doing that for 20 years" kind of style. Which is an extremely dangerous attitude to have imo. Shit, my old man was a doctor, if he thought like that he wouldn't have lasted 2 years in his job.
Another factor we aren't counting is ego. If you're a shop owner then you expect to be the local brain for all things within that field for your local population. Admitting your age old ways are outdated, or that your knowledge on a niche subject matter is less developed, well that takes some humility. And ego gets in the way of humility, especially if you're used to being the top dog for knowledge in your local area.
But the internet is full of bad advice so fair play to him. This place welcomed me and taught me so much without any egos involved. So I stayed! And every single day I am glad I did cause literally every single day I learn something new.
/EndRant