With all the streaming services available, there is far more high-quality content than I could ever hope to watch. Most new movies become available for inexpensive rental pretty quickly these days. If you feel you absolutely have to see a movie when it's released, then $20 seems reasonable; the studios have to make their money somehow.
That's what I was thinking also. When you consider how many eyeballs could be viewing that rental when they would be paying how much per ticket at a movie theater? With 99% of titles I don't mind waiting for a regular home release but I could see myself doing this for a movie that was really important to me. I used to go to the movies every weekend but rude people, high concessions cost, etc just killed it for me.