It is not a blame issue, but I have stated previously that Apple should allow the default mail, browser and map application to change. Hell you could even argue that the phone app could be substituted if Apple allowed it. But there are security and privacy concerns (not to mention competitive ones) that keep the walled garden....well....walled.Blame Apple for the lack of integration. Apple does not allow users to choose default apps.
I am okay with it, but tons of android followers are not. Such is life and the freedom to choose.