Your example of poor SERIALIZABLE performance is from a MySQL user. Have you tried SERIALIZABLE in PostgreSQL? The implementation is based on fairly recent research, and performs quite well for a lot more use cases.

And the point about ORMs is valid, but still not enough to back up your unqualified claim that using postgres would not have solve the problem. It might not have, but postgres offers a lot of tools to solve this problem (we didn't even discuss SELECT ... FOR UPDATE), and even inexperienced users are at least more likely to have stumbled into one of those solutions.

I very much agree that isolation issues are subtle traps for many users, even in SQL. I would like to see SERIALIZABLE become more common, and eventually the default, in postgres. I also like the fact that you're writing real tools to check up on these in a formal way.

But please be a little careful when making statements like that, because it can turn people away from the systems most likely to help them.