Middle of the night meanderings

Through no fault of my own, I am up working in the wee hours of the morning. Of course, this means I am sitting here waiting on a phone to ring, which may or may not happen. When I have chunks of time on my hands with nothing else to do but think of questions concerning animals, I come up with so many questions, the computer can't keep up with the speed of my typing.
My main question tonight is: Why do we label dogs? I remember when there were two kinds of dogs. There were purebreds and mutts. You could get either kind in any size you wanted, short or long hair. I remember Daddy saying mutts were the best so have always been partial to those kind of dogs.
Now it seems many people, even rescue people are always quick to put a label on a dog when the truth is they don't really know. Unless someone uses the failproof method of DNA testing, it is anyone's guess what a mutt is.
I remember meeting a dog years ago whose name was Hobo. I did not meet Hobo when he was a puppy, but he apparently looked just like a Jack Russell Terrier mix and was adopted out as one. Eighty pounds later, it was obvious he was some kind of hound mix. 
So, why can't we go back to those more simple times when a purebred was a purebred and a mutt was a mutt? Doesn't that make more sense? Just sayin'