First, I think it's almost a love-hate thing.
Skip grew up in Oklahoma City (in Cowboy country) and was immersed in the monster that became Tex Schramm's and Tom Landry's Dallas Cowboys. My guess is, like a lot of us who grew up in the Southwest, he was a big fan and was raised on the Cowboys.
As a young columnist for the Morning News, and then the Times Herald in Dallas, he probably overcompensated and began to look at the organization and the team with an extremely critical eye.
Like many artists (which columnists are .. they are writers, not reporters), he has a big ego. He saw the power in his writing (which was actually good at one time). He eventually wrote three books about the Cowboys, which I have mixed feelings about.
I think it thrilled him to take on the Cowboys, so to speak. In his first book, Skip writes about the "power" that is around the Cowboys and their players and even front office people. He wrote about how people (women in particular) were attracted to this "power."
As a columnist, it gave him a sense of power to spar (in print) regularly with the biggest of the big -- Tex Schramm, Landry, Brandt, Randy White, Dorsett, etc. It should be added that he has, on some occasions, been very complimentary toward the Cowboys.
He has done this sparring act at other places (vs. Jordan and Sammy Sosa when he worked for the Chicago Tribune, and vs. Al Davis in the Bay Area). Even last week, he was taking shots at Tiger Woods before the Ryder Cup coverage.
Skip went from being a talented columnist in the 1980s to a TV carnival act in recent years. It's jealousy and it's ego.