It is in fact so good that people can sleep in their cars and not crash -- and I wouldn't bet that the guy who sleeps in the car only did it once!
If you are going to compare it to human drivers, it also matters which humans you compare it to. Every time I drive I see people doing things far stupider than what a Tesla would do. Driving skill, and judgment, is so unevenly distributed in the human population that it would not be difficult to find a large number of humans who underperform the Tesla system.
It would be weird to punish Tesla for not being perfect. It has delivered self driving features that are already better than a lot of the humans on the roads today, and better than all of its competitors.
Let's go a bit deeper into your argument:
> Because people buy this feature because they don't want to drive (as a human); what does it matter how it compares to other self driving systems?
Ok, pretend you are someone who is looking to buy a self-driving car because you don't want to do the driving. Wouldn't you want to buy one that works well? It's a matter of life and death, after all. So you would do some research to find out who had the best systems. If you did that you would find out that Tesla's system, despite all the criticism it gets, is one of the few on the market that is worth buying.