I see what you're saying, and I even predicted that The Show would get mostly 8.0 to 8.5 type reviews before it was released. Why? Because their main new feature was the catcher being able to call the game in RTTS. This is something only baseball geeks will care about.
The mainstream video game press (and I'm not including OS in that category) feeds off of flashy new features. Many people spoke of Madden getting good scores this year and relating that game's quality to that of The Show. Well, Madden had Pro-Tak. On the surface it isn't a big feature, but it has a fancy name and it's something regular reviewers can grab on to. Think about the hit stick. Big deal, you can tackle using the R stick. But EA gave it a catchy name and marketed the crap out of it. Of course EA also has a ton of money to throw around to hype these things up.
Maybe SCEA should have called the catcher thing Catch-O-Matic 2010 or something like that. I'm being sarcastic, but I think you all get the point.