Typically it's called good PR. It's a way of making more money.
Perhaps if your cable company is small enough, there could also be a small element of altruism involved, but the chances of that remaining as the company grows large become negligible.
If the largest corporations wanted you believing in a flat earth, would you believe otherwise? If you don't believe the world's scientists on matters of science for over the last three decades, I think you'd believe anything all manner of nonsense.
Edit: Sorry, bit uncalled for..
In my small city the cable company bought the city a work truck, "donated by crony capitalist cable" right on the side of it.
Now I wonder why they'd do that?