There is a point when understanding what someone says becomes a little diffacult. For example, when you symply say Y, it could mean Y as in an unkown mathematical value, a Y chromasome, and doesn't traditionally mean the word that I figured you mean, whish is Why. Mst could be myst, must, an acronym. Well, I think you get what I am saying. I don't know about some people, but I for one actually had to look at that sentance to even remotely get what it is saying. Grammar nazis are often the same way and it can be legitametly annoying when your spelling and grammar is so bad that they have to stop for a few segundos to understand what people say.
Because we're human and we speak English. This is a computer, you're not texting; it's easy to type, so why not type correctly? We're all meant to understand one another, are we not? We learned to read and write for a reason: to communicate. I don't want to have to stare and analyze a sentence madami than just pagbaba it the way a person is supposed to. I know it's annoying when someone corrects your grammar, but if it's really that bad, then they should. To me in my opinion, I really hate "text talk'.