because you don't have to learn a code to send a text message. It can be done by anyone who has a mobile phone.
Mind you, I remember seeing an interview with one of the women who used to sit in huts at Bletchley Park, listening to German military morse code transmissions. She said that she listened to so much of it that she could tell exactly which operator was sending, simply by his 'touch' on the key. She's in her 80's now, but gave a stunning demonstration of how fast she could send - quite remarkable.