That may have just been because they want to emphasize a native mobile app rather than HTML5-based mobile experiences, and Google has not yet released their own native maps app for iOS.

Are you sure about that? Doesn't google have a maps application that is pending approval in the app store?

No, it's still being built and is probably months away[1]

[1]: http://www.theverge.com/2012/9/25/3407614/apple-over-a-year-...

Actually, the open letter also recommends Google and Nokia maps, via their websites (because native apps don't exist).

BTW: Am I the only one that thinks it's fishy that Google's claiming (a) they only had 3 months notice of this change and (b) 3 months isn't enough to produce their own iOS maps app? I don't believe either of those claims.

Why would it matter? If they decide to not release a maps app at all that would be their prerogative.