So this is still a problem. My iphone 4 was long overdue a replacement so I switched to an Android phone after IOS7 update (which, by the way, current problems notwithstanding - I am glad I did).
Happy with my new phone, however, I am not receiving text messages from iPhone users (including my wife) unless i ask them to disable iMessage from their phone.
This is what i've done so far.
1. Wiped my iphone (before I realised this was a problem)
2. Upon realising the problem, I logged onto my apple support page and 'unregistered' the phone.
3. Still not working so I've had to disable imessage on my wife's phone still and pretty much accept the fact I wont get text messages from any iphone users anymore.
4. Restored my phone from a backup, went to the imessage settings and turned it off before wiping it (still no fix)
5. went into apple store and told them the problem. The lady in bright blue told me that if someone with an iphone types my number in rather than my name it will send as a regular text (which it doesn't). Then she suggested that if iphone users turn their phone off it will clear it from the memory (also tested and it doesnt).
6. my current 'solution' is to send a blanket message to everyone who has an iphone to turn off their imessage when they send me a text (which i'm not going to do by the way), or even better, just cut off all communication with iphone users, right? Because it's my fault for not wanting to spend 3x the price to upgrade to a new iphone with the same/smaller screen size and similar specs as the andriod phone i got instead.
So when you say it's not a 'bug' I agree that using the most technical definition of 'bug' it probably shouldnt be called bug or glitch. What it is though is apple simply punishing me for not upgrading to an iphone 5 or 5c or 5s because of apple software being overly controlling.