All of your reasons for the price being what it is applies to the the exact other games people are talking about on itch. Everyone's itch purchases are one time only versus the patreon supporters monthly payments, everyone here is subject to the same cut that itch takes and the time it takes them to pay out, and everyone here is a little studio working from the heart.
People are shocked at the price because its significantly higher than everyone else around who is on the same system, which effectively leaves customers with no valid reasoning for the price tag.