I disagree, Google's long term play isn't to "own" a platform and have everyone live in it (a la apple/microsoft). Google is an internet company and it's overall strategy is to have everyone on the internet. Because if you are on the internet, chances are you will use a Google product (by choice).

Google doesn't care about iphone vs android. Google only cares that you are using the internet. An iphone/ipad is an expensive device for well off people. Androids don't have to be and less expensive products broadens the market. A market which when broader, is going to be owned by Google.

Making google maps a iOS product only encourages more people to use the internet and thus google.