We are talking about a very delicate electrical system that cannot function effectively outside of a specific radio bandwidth before being completely overtaken by the numerous sources of RF which exist in the world. Remember radios? Well, they got their name because they were the receivers of "radiated" "waves" in the air. As were TV's. Guess what? That coax line in your house? That's the modern version of an antenna. CATV literally means "community antenna television". It's an antenna that you share with everyone on the same "node" of your cable system. It's shielded so the RF no longer has to go through the air. In effect, if there is a breach in the shielding around that cable (a long antenna), you're going to get noise, and crappy service. Additionally, your precious internet rides on the highest frequencies carried by this sole, frail copper wire. Those high frequencies, as any EE student can tell you, are especially highly susceptible to interference. A single dB can make all the difference for your highly calibrated, sensitive cable modem that you don't fully appreciate. Some of these networks are huge. If one of your neighbors got high and plugged a blender in, anywhere in his home, and he has frayed cable jacketing, anywhere in his home, or a bad fitting, anywhere in his home, it can easily take an entire block down. There are hubs, of course, but don't count on one being nearby, if you're tasked with repairing someone's internet. I get it, "fuck Comcast, they're the devil because I have to give them money", but let's be adults here. Comcast is people. Every company is people.