I have many nerdy friends who have been Linux users for ages. But most of them don't know such a thing as Openwrt exists or have never bothered to give it a try.
It's a very fun piece of software to play with and can be extremely useful for routing traffic.
Wondering why it isn't more popular/widely used.
Anecdotal, but I only see OpenWRT out of the two in commercial products which hints to me its better supported (e.g., security patches and feature support).