That's a good point. When I am making okonomiyaki at my table, it is just for me. I am not making it for the person that sits at the table after I leave. At the very least, I don't think gyoza vouchers are an acceptable form of compensation in Japan (how do you pay taxes on gyoza?). It's fun to riff on, but overall I have been really enjoying this series so far.
As for random downvotes, it happens everywhere occasionally. I suspect it is people seeing things they might not like when they browse the "all" feed of their instance rather than "subscribed". They are just random internet points, they don't matter at the end of the day.
Oof, this one lands a bit close to home. Teachers can be amazing, but comments like these with the best of intentions can sometimes hurt given the context of a person's life.