My d is in college, and the major way she communicates with her friends is through texting. They all have different schedules. She doesn't need to remember that one is in class so shouldn't be called from 11-2 on Thursdays, but another can be called then, etc. She can text more than one at a time if they're trying to arrange a meeting/rehearsal/meal without having to deal with conference calling. They're all on the same messages so everyone knows what everyone else is doing.
I can text her without worrying that her phone will ring in class or at work; she can do the same for me. If we can respond immediately, we do; if not, we wait. (We also talk to each other, by the way.)
She texts much more than she talks, so we've reduced the minutes on our plan. I save more that way than the unlimited texting costs.
And yes, her college fund was fully funded and we can put food on the table. Retirement? Well after the financial meltdown, that's a totally different story.
Why do parents pay for texts? The same reason we pay for cell phones, internet, cable TV, etc. I remember this conversation a few years ago. "Why do kids need cell phones? We didn't have them and we did just fine!" Society adapts to new technologies. And kids adapt quicker than most.