Way back I was working on an in-house inventory app written in Visual Basic against SQL Server 2000, I think. That one just put locks on tables. It had the "charming" characteristic of that if you weren't very, very careful with Enterprise Manager, loading a table in the GUI put a lock on it and just keep on holding it until that window was closed.
Then the running app would eventually snag on that lock, maybe keep holding some other lock that something else would snag on, and 5 minutes later I'd hear one of the operators screaming "Nothing is working! I can't take any orders!" from the room next to me.
MVCC is great, but this article does identify some of the puzzling design choices of the Postgres implementation. The index problems are particularly bad, and seemingly avoidable.