Just some notes on what I have seen:
-This is not a glitch, it is the way the software is designed. It was done on purpose. It places responsibility on the user.
-You need to remove more than just your phone from iMessage!!! Just removing your phone accomplishes nothing; the iMessages will still be sent as iMessages, just to your iPod, PC or iPad. You must remove all devices from iMessage.
-You won't recover iMessage Group functionality. iMessage is a fairly dry, weak version of free products such as Line, Skype or Kakaotalk. It is an Apple exclusive application with no cross-platform compatibility. If you leave Apple, you lose iMessage. It is just an inconvenient app that comes preinstalled in all Apple products that suckers have unfortunately become accustomed to.
Plea to Apple:
You have a product that has the reputation of anyone "being able to just pick it up and use it." I have seen enough uninformed people leave Apple, then blame Android for this debacle. It is clear that this is the desired effect, but that is a dick move. Just add a radio switch below "iMessage: On/Off" that says "Deactivate iMessage for all devices? Yes/No."
Problem solved. Your user experience is salvaged and you don't have masses raging at whoever happens to come to mind first.
Better yet, create the iMessage app for android and charge users some price to switch. Increases your market, gives iPhone users an opportunity to salvage group chat and you can still punish those who stray from your product line. iMessage is a ****-poor alternative to the above mentioned products, but you already have the consumer base so this is purely an opportunity for profit.
If you have any thoughts or would actually consider this, let's talk.