Text Lingo should always be Text lingo

So I understand the reason behind text lingo. What I mean by text lingo is the abbreviations you use while texting in order to reduce the amount of buttons you need to push and also to shorten the length and time it takes to complete the message. Especially if you have Verizon and they only allow you to send 160 characters to outside networks. The lingo is needed in order to text a full long message. For example:

OMG: Oh My God
WTF?: What the F#$k?
IDK: I don't know
ur: your

I think you get the picture. What I DON'T understand is when people use the language in real life when you speak.

I was at work and I had asked a young employee a question.

He answered "i-d-k."

At first I had no idea what he said because I was expecting an answer in full English.

I said "What?." He repeats.

I tell him I am not texting him and expect him to answer in english not text. When I asked him why he would respond in text lingo all he had to say was that he didn't want to say the words. Then goes on to say some random text lingo phrase and at that point I lost interest.

The sad part is he is a really smart kid and he made himself sound like such an idiot answering that way. I am hoping he was just doing that to show off and he actually doesn't speak that way to his friends on a regular basis. Actually, I hope this isn't common amoungst his age group because if so it makes me loose faith in the next generations moving up in this world. I can't imagine if one of them is going to the one to cure cancer that they would answer a question with "o-m-g" or "i-d-k"