And maybe NFL over-exposure.
When MNF started, it was a novel experience.
Then TNF came along. And Sunday night football. And an NFL cable channel devoted exclusively to all NFL Football, all the time. And NFL commercials in the off season to remind us the NFL is still there (as if we could forget).
Meanwhile, cable exploded. Offering more alternatives, including sports alternatives.
The concept has gone from new and exciting, to part of people's watching experience, to old.