Incidentally, that aspect of Maltese dog behavior is not just my personal opinion or conclusion. It's actually part of the information contained in the breed standard. They should not be left alone (w/o human companionship) for more than 2-3hrs at a time and even then not daily. It is said to be unduly stressful for them, painful even. I didn't know this when I bought my 1st Maltese.
Maltese are very cute but are also extremely high maintenance. This makes them subject to abuse as people buy them for their cuteness and then grow frustrated with the extreme amount of work required to care for them. Consequently, it is actually very difficult to buy a Maltese puppy from a conscientious breeder. It's easier to get a security clearance than to be cleared to buy a Maltese puppy from a conscientious breeder.
Before a conscientious Maltese breeder will consider selling you a puppy, you 1st have to answer a boatload of questions and provide documentation & evidence to support your statements. If you had a dog previously, especially a Maltese, you have to provide the name of and access to the veterinarian you used and also the groomer (so the breeder can assess whether the dog was properly cared for). If you live alone and have a job, they will ask you who will keep the puppy/dog while you are at work. If you say that you plan to leave it alone, most breeders will refuse to sell you a Maltese puppy (because they are not to be left alone all day). Widget used to stay in doggie daycare while I was at work, because he got into too much trouble when left alone at home.
I found the process of buying a Maltese extremely heartwarming due to the care that is bestowed upon these dogs by conscientious breeders and due to their unwillingness to sell to just anyone. It is, however, equally distressing to learn that the reason for all of this is the neglect and abuse these sweet but ultra-high maintenance dogs often endure at the hands of buyers who fail to realize the amount of care required for that cute puppy.
When purchasing my 2nd Maltese (Widget), I talked to about a dozen different top breeders around the country (Widget was flown here from elsewhere in the country) and got the same basic deal from all of them. I would approach them as someone who was there to buy a dog but would quickly learn that I would 1st need to sell myself to earn the right to purchase the dog. They would not sell the puppy until and unless all of their requirements were met and they were sure the puppy was going to a home where it would be cared for properly. And it was very much the opposite of our court system. I was always presumed guilty and required to prove otherwise. It's much easier to get approved if you have had a Maltese dog before and can provide proof (vet & groomer) of proper care. It's much harder for 1st time buyers, because breeders know most people don't realize the work and expense involved in caring for these dogs and also know how quickly people grow frustrated with the high maintenance and end up abusing or neglecting the dog.
When I was looking to buy my 2nd Maltese (Widget), I was extremely responsible, had a very good job, & could provide proof that my 1st Maltese received excellent care. She had a very aggressive cancer at age 2, had 3 major surgeries that were quite expensive, and ultimately lived to age 11, even though Drs didn't initially expect her to live more than 6mo past diagnosis. Despite having all this going for me, over half of the country's top breeders turned me down. I was standing there holding the money, and they would not sell me the puppy.
The breeders who turned me down did so for 2 reasons. Some refused because I wanted them to send the puppy (alone) by plane; they would only sell me the puppy if I drove across country to pick it up in person. They said the trip alone in the plane's cargo area would be too traumatic. They were right, btw. Widget took that trip, and to this day (11yrs later) he has to take Valium to ride in the car. Widget sleeps like a baby through thunderstorms and 4th of July fireworks but panics when you turn the car engine on. A few who were willing to send the dog by plane still would not sell to me, because I had a job and planned to leave the dog home alone during work hours. As I mentioned above, Widget ultimately ended up staying at a small, doggie day-care (adjacent to and run by his vet).
Unfortunately, there are always the unscrupulous dealers who will sell you anything for a buck, but I did find it heartwarming to realize the extent both the Maltese Assoc and its conscientious breeders go to keep these dogs out of the hands of people who can't or won't take proper care of them. Maltese dogs are extraordinarily sweet. I bought my 1st one for the look, but I bought my 2nd one because they are so amazingly sweet and eager to please. That said, I will not buy another; I no longer have the energy to deal with their maintenance needs which are HUGE (beyond anything you can imagine).