First off, let me state that this is a stupid discussion. I couldn't care less if Obama confused Comiskey Park with Shibe Park. It has no bearing on his abilities as a President.
However, things like this (along with the ridiculous discussion of whether it did or did not bounce) became topics of discussion after
1) the press mercilessly hounded Bush for the slightest mistep, mis-pronunciation, etc
2) Everyone went to such great lengths to cover for him (including Fox Sports) and
3) Obama himself pokes fun at Cubs fans for not being serious about baseball.
Come on - if you can't throw a baseball, bowl, or just aren't an every day Sox fan, that's fine - just don't pretend otherwise. Be who you are and let us judge you on your policies.