Because generally, people who breed mixed breed adults and give the puppies stupid names are in it for one thing. Money.
Sometimes they look after the breeding bitches well but more often than not they are puppy farmers who tend to keep the mum dogs in very poor conditions, overbred then disposed of.
The pups themselves can be underage, often have worms or fleas, often unwell.
They generally don't health test because it's VERY expensive, each breed has its own set of inherited diseases it is prone to and each breeding adult should have the necessary tests like heart scans, Dna samples, hip and elbow scans etc.
When this isn't done, a puppy appears healthy, then, in later life, it suddenly comes down with disease - sometimes so crippling that it needs to be euthanised at a young age.
If your unlucky enough to get a puppy that later goes blind at just a few years old or loses the use of its legs or any of the other myriad of diseases, good luck getting your money back off these people.
The personality isn't always what you expect, they can be full on poodle or full on schnauzer or a mix.
They are extremely expensive too.
It's much better to get either a poodle or a schnauzer from a proper breeder who health tests thus guaranteeing your puppy won't develop a genetic, crippling disease, good breeders are always there to offer advice too which can be invaluable.