Cable ratings are generally low to begin with. Most stations draw their best hours in the rankings of maybe a million people. To give you an idea, Sci FI's biggest hit before ECW was BSG, which did something like a 1.1 on its miniseries premiere.
You'll notice that Network ratings bury wrestling alive. Every week. Without excuse. Reruns kick its ass.
Cable is a different breeding ground. For one thing, there's like 900 cable stations and maybe 30-40 network if you're in a decent area. That doesn't mean that's a factor here, but it's still one of the major differences. Cable generaly doesn't have the same shit on four channels, I get five NBCs alone. Don't get me started on CBS, either.
Further, EVERYONE gets broadcast. It's a less specialty market. More people will watch even bad shows just because they're on. Cable? Pay for it (In theory). You don't necessarily get every channel.
Though the main reason? There's garbage on every station. So even bad wrestling? Looks good in comparison.
