There’s nothing about text messages or email that requires them to be written in such a manner. Laziness and sloppiness are the fault of the users, not the technology.
If you have any doubts about that, just go out and look at the serious decline in driving skills these days. The cars are better, safer and more advanced than ever, and yet the drivers seem to get dumber by the minute. This is because the technology has effectively reduced (or eliminated) the cost and/or consequences of driving poorly.
You can say the same thing about almost any amenity that has become commonplace in our modern world.