Why isn't this storm warned?

There are many reasons why a storm may not be warned.

1. The rotation isn't tight enough to create a tornado.
2. Storm Spotters have not seen any rotation at ground level.

Just because there is a hook echo on radar doesn't mean it's a tornado. One good product to look at is the velocity. If you see a tight red and green mix, that is a decent indicator of a “radar indicated tornado”.

Instead of second-guessing the NWS, let the NWS and the trained people out in the elements do their jobs and trust they are doing it correctly. Once in a while something is missed, but that is why the NWS, Storm Chasers, and Public Safety all work together to ensure your safety.