One of the issues with that is that it's not that simple to select whether you want to send an SMS vs. and iMessage. By making it "smart" Apple also never really provided a simple way for a user to control that part should someone want to do that for whatever reason.
hi
you are so correct about this. i have often wished that apple would give us a way to indicate before hitting the Send button, whether or not we want the message to be sent as an iMessage, or, as an SMS. instead, as it is now, we need to wait sometimes up to 2 minutes for the indication that the message was not able to sent as an SMS and then selecting the 2nd time it is to be sent as an SMS.
i think a simple way for apple to handle this is for the User to use the "phone type" in Contacts: you can designate a phone number (even now) as Home, Mobile, Work, Fax, and as iPhone. If the number is designated as iPhone then the User preference would be clear that the message should be sent as an iMessage. If the user simply designates the phone as a mobile then the preference should be understood that the user wants it to be sent as an SMS.