I think that the problem with texting is that teenagers are no longer able to express themselves intelligently (or at all) because they are constantly texting. They don’t know how to carry on conversations and they’ll say things in their texts that they would never dream of saying out loud- thus leading them to talk to someone (probably of opposite gender), who they would never talk to in person. I think that this is why Rabbanim are so against it- teenagers are too addicted (and any addiction is bad) and they might come to have relationships that they would never have in “real” life.