In all likelihood, MMS is just the standard for a group message due to the slightly larger overhead even though you are sending only text. It technically has to send that text times the number of recipients and even though that is still considerably less information than a picture, I would guess it's yet another dick move by big telecom to rake in more money.
SMS/MMS should be free, and it can be:
- Get a Google voice number
- Install/configure Hangouts (also integrates with chrome)
- Set Google voice number in hangouts to the default sending number
- Free MMS/SMS over data
- Added bonus: Free phone calls with Hangouts using Google voice
You can still have facebook as well as the stock messaging app on your phone and choose to use any of the three at any point in time. They should all synchronize to a degree.
An alternative workaround would be to send the message to one person, and then copy the text and send it to the next person, etc.
Also worth noting just in case:
If you add a Subject to the message you're making, it gets converted
to MMS format. Even if the Subject is empty, at least, that's what I
It is also relevant how many characters are being sent. If it is > 160 (or perhaps another close number), there is a good chance the protocol gets bumped to MMS automatically.