Although they may be useful on mobile phones, to avoid the cost of speaking, and to save time due to the totally inadequate keyboards, - oh, and of course to save time while typing in chat rooms and on forums, - they erode, and cause deterioration of the language.
On a site like this, the asking of questions, and answering them, depends on understanding and being understood. There are a vast number of Blender users to whom English is their second language, and it can be quite a difficult language to learn! Why throw in 'curve balls' which, even to English speaking people, can be hard to understand?
There are times when I'm not sure whether I'm reading a typing error or a 'text'! We should try to keep it clean and precise (or we'll end up with no language at all!).
I post this at the risk of upsetting a few 'lazy' people. :)