Why do carriers block features?

Sometimes the answer to this question is obvious. Verizon blocking google wallet was clearly so they could force people to use their own wallet app, whatever the hell it was. What I want to know is why on my AT&T Note 5 I don't have Auto Restart or Smart Manager. Both very useful features I would love to have, blocked by my carrier. How do either of these features effect AT&T? I'm sure there is plenty more blocked that I just don't know about.

Does anyone have any insight as to a logical reason a service provider would want to block stuff like this?

Here is a link to the video where I discovered these missing features:

https://www.youtube.com/watch?v=OPD8Aotsewg

Please excuse how boring the guy talking is.