There are several shows that are in HD and are not compressed. My dad is a digital cable subscriber but still switches to OTA when the show is available because cable has so many compression artifacts. I use OTA only but I am a hold-out. I just hate paying for programming that contains ads. I mean, isn't that what the ads are for?
Vote with your wallet; cancel your cable subscription if your cable company is re-compressing the stream.
Here in SoCal, Cox promised to never recompress the raw signal they get from the networks, so whatever we see is the network's fault, not theirs.