The reputable breeders I know may, other than a spouse, have one assistant to help pick-up poop, feed, groom, and walk the dogs but if they didn't have an assistant, it wouldn't be a big deal.
These folks have 88 puppies for sale at one time! A reputable breeder might have 88 puppies during the breeder's entire lifetime. There is no way these dogs have the care and the socialization necessary to make a happy and healthy puppy. Sure you might be lucky and get a wonderful, happy, healthy, puppy but you'll be paying way too much and the puppy won't be selected to fit your lifestyle. Reputable breeders do Puppy Aptitude Testing (PAT) testing to find the right dog for the right person and usually won't release a dog until, at a minimum, 8 weeks. Many wait longer.
Ask yourself. Could you give enough love and attention, handling, and socialization to 88 puppies at one time? Even with 3 people working the kennels around the clock, that's 29 puppies per person. I'm talking real workers, not animal or child or relatives on the couch.
If you want a Maltese-Yorkie cross then great. No reason a mixed breed can't be a delightful, loving companion dog. I have no objections. That isn't the issue here. The issue I have is that dogs that come from places like these are usually taken from their mothers too young, have less than ideal veterinary care, and are poorly socialized. The dam and sire are usually chosen for small size rather than good temperament and you're supporting a kennel that appears to breed its bitches to death.
You'll hear so many people on this board advocate getting a purebred dog because it's easier to predict their temperament and when you stick to one or two breeds you come to know the dogs inside and out. You learn which dogs are suitable for which home and it's much easier to predict possible health issues. This is good for you and your vet too. Mixed breed dogs are much more of a gamble. That's the primary reason. It's not snob appeal, it's making sure you get the most dog for your investment. The last thing you want is an adorable puppy who turns out to have the personality of a monster, has been poorly socialized, and may have health issues you won't know about until after the warranty has expired. Far too many of these mixes end-up in shelters because their owners got a dog that never quite adjusted to home living. It's most essential for young puppies to be handled daily soon after their birth, for their dam to be a full family member, and for them to live in the home. There is no way this breeder's house has 88 puppies that age running around the living room or kitchen.
I would suggest, and I mean this with every consideration for your future happiness with a new puppy, to investigate a breeder recommended to you from the AKC breed club for Yorkies or Maltese. You may have to wait for a puppy, but if you do, it means your puppy will be healthy, well-socialized, and the right temperament for your home. Your pup will be registered, will have a pedigreed health history, and your pup's vets will know what issues to look for in each stage of the dog's life. Your breeder will be a phone call away and be eager to hear about their dog, be willing to help you with problems, and be willing to take the puppy back should you be unwilling or unable to care for it in the future. No dog pound for your pup, just good, loving, homes.
Their faces are cute but it's like anything else you buy. You don't want to fall for fancy advertising when the product isn't what it seems to be. Please wait, do some research on reputable breeders, and then consider your next move carefully. A few months of patience and research can mean years upon years of happy dog ownership.