Pragmatics studies the factors that govern our choice of language in social interaction and the effects of our choice on others. - David Crystal

I believe that any form of writing exercise is good for you. I also believe that any form of tuition which helps develop your awareness of the different properties, styles, and effects of writing is good for you. It helps you become a better reader, more sensitive to nuance, and a better writer, more sensitive to audience. Texting language is no different from other innovative forms of written expression that have emerged in the past. It is a type of language whose communicative strengths and weaknesses need to be appreciated.

There is little scientific data on the point, but evidently people do speak to themselves.

Micro computers used as word processors complement the audio facilities, enabling the interactive teaching of all four language skills reading, listening, speaking and writing.