Well on the one hand I agree, that is what people do... right now. On the other, I see where Apple is going with this. They're trying to "untether" us from phone numbers. Only then can we move forward technologically. That is, the freedom to communicate seemlessly between any internet-connected device. Think about it... with voip, you can call anyone from any computer, tablet, ipod, whatever. There's really no reason to use the number-based voice system anymore (other than that everyone already does). The concept of a "phone number" is outdated and should be retired. Of course, cell phone companies don't want this to happen. They make a lot of money by locking people into their plans and making it hard to switch networks.
The future is internet IDs (like an apple ID). Take it with you anywhere, use it for all communication (email, voice, facetime, etc) on any device. Apple is once again ahead of the curve and trying to force change a bit early.
Agreed with everything you said!
However, that is also kind of the problem. They are so far ahead of the curve that the change they're trying to force through is a bit _too_ early. Due to the fact that people use cellphones with a phone-number and not an email-address, the whole iMessage-deal creates extremely redundant information in our text-messages.
I've been trying to tell my friends to text me on my mail instead so that I recieve the text on all my devices, however, this creates several problems.
1. They will now have 2 text-threads for the same contact(me) which can be confusing
2. If they're using the email-one, they won't have access to the history from our previous texting when the number was used
3. If they're using the email-one, they can't send a regular text-message so they have to go back to the old one - thus creating problem #2 again but reversed
IMO Apple should instead try to integrate both number and email into the same message-thread. Have the message sent to the email as standard if there's an Internet-connection. All messages sent this way will be sent to all devices. If for some reason the sender doesn't have Internet-access, have it send the text to the number instead. This message should still be in the same conversation-thread, only that it's marked green as usual(and perhaps a "details" option for each message if you click it, where it will display information about what ID the message was sent to, number or email, etc.). Messages sent to the number will obviously only show up on the phone-device so the problem here is that part of the conversation-history will only be available on the iPhone.
There's a workaround for that. Have these messages that was sent to the number marked as "Offline" or something. When either of the phones(sender or reciever) has Internet access again, have it "upload" the offline messages to iMessage. If it's the sender who gains Internet access, the message will just be resent as a regular iMessage, thus making the message being sent to the email and pushed to all of the reciever's devices. If it's the reciever who has Internet-access, have their iPhone upload that message as an iMessage, thus pushing the message it recieved onto every device the owner has.
Voilá.
Some things obviously needs to be figured out but I believe this is a much better way to transition into an email-ID for phones rather than just boom bang like they're doing now - even if it's the future.