Every TV channel gets some money per subscriber per month from your cable/sat company. The bookkeeping is complex with 100-400 channels available.
It is also very hard to transmit only some channels and not others to homes without a smart cable box.
There are also some 'specialty' channels that would go out of business if they were not bundled with more popular channels to help them out.
So TV channels are 'bundled'. This lets the cable company group channels into blocks they can enable/disable. It makes the bookeeping simpler and helps smaller channels stay in business.