Why are mutts now considered breeds?

Lots of breeds of dogs came from some sort of mix. Some breed for temperament , some for the hair care, and the allergenic property's of a dog. They attach a designer name and poof you have a 400 plus mutt to sell ... the ones bred with poodles half of them are not hypo allergenic ... these nuts even have like some kind of scale to say what is what... i have a so called designer dog he has hair not like his ancestors he has this chihuahua coat smooth and some kinda crappy coat with a mowhawk of white fluff he is a chi - chi barf !!! The worlds ugliest dog was one of this breed .. I got him as a rescue... the only reason I took him was that he had attitude, and a face only momma could love, and was to be sent to a kill shelter ... but they sell this breed for way high. he is half chihuahua and half Chinese crested ... and so cute !!! but that is my opinion