Why are internet providers so bad at providing service to their customers compared to other types of services?

I keep seeing ads for Centurylink at '$65 for life', so I decided to go see the details of the offer and read some customer reviews. Ouch. I'm not even sure Comcast is that poorly rated.

Also, I'm not sure how [one star and a half equals a 2.5 average rating.](https://i.imgur.com/XlQdovt.png) That seems like fuzzy math?