Imagine having a business model so fragile that your only line of defense is to obscure the cancellation process through these tactics. Do they really think that they can curve their churn this way? I mean best you’re doing is getting maybe another month or so of revenue from a customer who is just pushing the pain of cancelling because they are busy or lazy. And at the end instead of getting what could be a dormant…
Yes, because it actually does work. If you need proof, just call up one of these companies and say "I am cancelling because your service is too expensive." Odds are decent that you will get some type of promo offer to keep you. If there is any competition in your area for internet/cable and you have never done this, you are wasting money.
OP could have also had any number of other problems that could have been solved by these retention specialists. Basically they are doing the equivalent of an IT person asking if you have turned it off and back on again. That might be frustrating for the type of people who read HN and know better, but the reason they ask it is because there are legitimately issues that can be solved by this extremely basic level of support.