Yep, this is the answer. Tons of people are trying to cash in on dog breeding like beaniebabies. Frenchies, pitties (including XXL toadline monstrosities), random mixes (shitpoos, bernadoodles, cockadoodles, etc), etc. Breeding rights, stud fees, etc. are big business and essentially none of these "breeders" have any clue what they're doing.

In the vast majority of places in the US, there are no requirements or certifications needed to breed dogs. And now people will pay insane amounts of money for frenchies with rare coat colors, or pitbulls that are bred solely to be huge and squat with no concern about temperament or health; so irresponsible, backyard breeders who either ignore or are completely ignorant of proper breeding practice and refuse to get or can't afford proper genetic testing and medical care for their animals, are breeding for phenotypes like coat color or being insanely huge and squat and breeding in serious congenital defects and abnormalities.

Then either buyers are stuck with these shitty, genetically fucked up dogs they paid like $5k-10k for that now need thousands more in veterinary care to treat all the issues bred into the dog (not to mention parvo, parasites, heartworms, etc.). Or the breeder's little business collapses when they realize that they can't afford to continue operating their shitty puppymill due to the fact that dog breeding is expensive and their fucked up breeds can't give natural birth and so all need c-sections. But, it's usually the first one because there are no shortage of buyers willing to pay stupid amounts of money and trust the "breeders" because they assume they're experts.

So people often end up dumping the dogs when they realize they can't care for them medically or are aggressive or whatever else, while backyard breeders continue to pump out fucked up dogs for profit.

Yup. It needs to be a crime punishable by fines and prison time. The average lifetime cost of owning a dog can be as high as $50,000. Use that as a baseline for fining people who breed dogs while shelters are turning them away.

Pitbulls, pit mixes, and the occasional incredibly neurotic Chihuahua (rated the most aggressive breed when individual dog owners have been surveyed on their own dogs' behaviors).

Be mindful when reading the sources. This is a very polarizing debate, and it isn't really as clear as "pitbulls are little angelbaby velvethippos" or "pitbulls are vicious killing machines".

Pitbull is a range of phenotypes, not a breed. What we call pitbulls commonly are a mix of boxers, Am Staffs, bulldogs, american pit bull terriers, bull terriers, etc. So, we're relying on police to ID these dogs after a bite has been reported, and so a large number of aggressive individuals of a variety of breeds/mutts might get lumped into "pitbull" by cops.

Also, dog attacks are more likely to occur in lower socioeconomic status neighborhoods where dog ownership practices are often less responsible, and cops are more likely to be in the first place. Pitbull-type dogs are more likely to be owned by lower SES individuals (in part because they're so prevalent, but also due to cultural factors). So, it is likely that pitbull-type dogs are overrepresented by these statistics.

That said, it is wild that people claim that breeding does not impact behavior. Pitbulls and various bully breeds have often been bred to be aggressive and to guard territory, just like Cattle Dogs have been bred to nip at heels and keep creatures in a herd. Any cattle dog owner will tell you that their dog exhibits herding behavior even if it's never seen a cow or sheep. It's the same with some pitbulls and they happen to have one of the strongest bites of any type of dog coupled with a behavior where they latch on to the thing they've bitten and won't let go, but will continue to thrash around causing major tissue damage. Contrast that to German Shepherds, another dog that makes up a large number of dog bite cases. Their bite force is less on average than that of a pitbull and most German Shepherd bites are fear-aggression related because GSDs are extremely neurotic and anxious (also due to breeding), so GSDs tend to bite and release unless they're specifically bite trained, like for police work.

So anyway, just be aware that both sides of this debate try to put spin on it, but breed characteristics do matter, and our recordkeeping of dog breeds and bite statistics is flawed essentially due to the problems extant in law enforcement broadly.

The stats are easily manipulated by either side. The fact of the matter is that, given the number of attacks on humans and animals by pit bulls, and the average age of pits, roughly 1 in 10,000 pits will attack something in their life. This is an order of magnitude more frequent than rottweilers (the next most dangerous breed), and when a pit bull attacks, it's more likely to kill its victim than any other dog breed.

1 in 10,000 is large enough for some people to say the whole breed needs to be euthanized, it's small enough for some people to say that it's negligible, and it's at just the right spot for me to say that it should be illegal to breed them, but existing ones shouldn't be euthanized.

https://www.forbes.com/advisor/legal/dog-attack-statistics-breed/

Dog Attack Statistics by Breed

Many dog advocates argue that there is no such thing as a bad breed, only a bad owner. Still, it can be helpful to understand which breeds of dogs are most commonly involved in bite incidents or acts of aggression. Dog attacks by breed statistics are invaluable both for individuals looking for a dog to adopt as well as for those who interact with animals who want to minimize risk.

The breed that commits the most attacks overall is pit bulls.

Pit bulls are involved in more dog attacks than any other breed. In fact, the American Animal Hospital Association reports this breed was responsible for 22.5% of bites across all studies. Mixed breeds were a close second at 21.2% and German Shepherds were the third most dangerous breed, involved in 17.8% of bite incidents.⁶

The breed that is most likely to be involved in a fatal attack is pit bulls.

Pit bulls are both more likely to be involved in bite incidents and more likely to cause serious injury or death when a bite does occur. In fact, from 1979 to 1998, the Centers for Disease Control and Prevention determined pit bulls were involved in the most fatal dog attacks, accounting for 28% deaths due to dog bites during that same time period.⁷

I'll add, I like pitties. I'll also advise taking this with a grain of salt as so many mixed breed dogs fall into the pitbull umbrella.