MVCC and optimistic concurrency control are very pleasant to work with for anyone who spent a decade with manually locking SQL databases. It takes the human error and developer mistakes away from the process, or protect against it. You can still slow down your queries with deadlocks, but at least you cannot corrupt your data by accident.
Though, any other optimistic concurrency control scheme can be better, but PostgreSQL was at the right place at the right time when people started to leave from MySQL.