I don't get this part? Can you clarify what part is a hassle? ESTA just seems great to me: fill a form online and get (most of the time) an "immediate tourist visa".
When you're from a country that isn't in the ESTA program, then it can be a hassle!
You don't really get a visa, but an approval for visa exemption I believe.
However, after checking, it does seem like the site has improved a lot. It's been a while :).
The whole concept goes against the concept of visa-free travel. No matter what they are termed those are effectively – usually automatically processed – visa against the spirit of bilateral visa-free agreements. It used to be that you can turn up at the border to apply for entry there instead of beforehand. Those "travel authorizations" are a step back. Not to mention all the data footprint that this process creates additionally.