Hmm. I guess I'm the only one that wants this.
You're not and that is a small part of why so of us jailbreak.
Think of it this way, they're a lot of people who will laugh at the idea of coloured text bubbles but if Apple ever do let you change them in the future a lot of the people now laughing will think it's such a great idea.
Think back to +5" phone screens and how 'some' people laughed at them, I wonder how many of those laughing people now have a plus model iphone? Ironically the plus model iphones are the biggest 5.5" phones on the market.