Because he's a play-by-play guy, he's not an analyst. They are two different roles. The color commentator goes into the weeds with technique, nuance. That's not what the lead broadcaster's role is. Shane's knowledge on the sport is more than the basic "down and distance" type of thing, but he's also not going to throw things at you that drown out the important things - the action on the mat.
I will whole-heartedly agree with you on one point though - we aren't the target market. Hell, I'm fortunate enough to be a voice at the NCAA championships and I know most of the fans in the building know more about the sport from a technical point of view than I do - but my role isn't to explain the sport to people. It's "down and distance" with a sprinkling of stats, history and nuggets of information. I live in the weeds with the stats and records, but I don't with the technical parts of the sport. Those of us on the boards usually fall under the umbrella of "we already know about what we're watching" so you're right there. We aren't the target demo.
I've spent a lot of time on the broadcast side for a number of sports - the guy leading the broadcast is going to focus on leading the broadcast and setting up the analyst. Too much inside baseball for a niche sport like wrestling would turn more viewers away than it would bring them in. We'd still watch, but that's about it.