Yeah I don't mind win probability as a tool and certainly didn't bother me showing up in the top corner of the broadcast. I don't know how much it adds to like, the entertainment value of a game? Given Kyle's first point above, do you really want to showcase that (making up numbers) being down 2 going into the 8th only gives you a 20% chance of winning? Seems more likely to drive people off than keeping them interested.
On the gambling side of it, it seems counterintuitive just because I assume at a very rough level that in game live betting odds mirror the win probability chart pretty closely, but for the (ever growing) spreads that the casinos bake in to the odds to make sure they get their revenue. I think it's pretty likely that tracking win probability against the live odds you'd rarely see like, some sort of value proposition available, which to me would lead to decreased betting having it put right in front of you. Then again, maybe they're just counting on the anti-stats crowd to get angry and try to prove a computer wrong or something.