I like their stance on it:

> This system is very much symmetric. A transaction that commits generates pretty much the same amount of work as a transaction that aborts. This is very elegant, but it’s not best in practice, because very few people run workloads where anywhere close to 50% of transactions abort. (Anyone who has such a workload will, I suspect, find that PostgreSQL handily outperforms the competition.) It would be better to have a system where we try to make commits cheaper, and aborts more expensive.