Pretty sure I hadn't heard that before. Wp though.
Referencing wild animals is compelling but also isn't that clear cut. I don't know any wolf owners, but there are plenty of examples of people with first generation wild animals as pets and there are people who own animals like raccoons or pouched rats that have a tendency to be only a few (sometimes one or two) generations from wild. You get a lot of problems with it but also some great results. Raccoons, for instance, similarly to monkeys, very often become a big problem when they hit maturity, but plenty of them go on to make great pets. Pouched rats are highly intelligent and can be trained to do all sorts of things without thousands of years of domestication (
https://www.apopo.org/en) but tend to be quite destructive and can become aggressive if not well handled as they reach maturity. I know people who have tamed squirrels and such, and someone who owns civets, a kinkajou, and some other rare animals. You can find people who have trained foxes. There are varying degrees of whether you'd consider them "pets" in the companion animal sense, but most are well tamed and very handleable.
Wolves tend to be a lot less responsive to training, like to be domineering, have a much smaller socialisation/attachment period, and don't play so well with other dogs and animals. Still, you can find trained ones (it's hard to find many definitive examples because you can't be sure whether they're crossbreeds, and the internet is full of "wolf-dogs that are probably not very close to actual wolves other than appearance).
Genes influence behaviour. There's no way other than some biological components to explain why dogs are far easier to train than cats. The open questions are how much and to what extent environment play a role. When it comes to the differences between domestic breeds, it's definitely not clear cut that a pitbull's genetic predispositions are a long way from a chihuahua, and even less clear that any such predispositions are anything like insurmountable problems to a competent owner and handler.
One of the reasons dogs are so popular is that, for the most part, they genuinely enjoy training and respond to simple rewards. This isn't a component that, as far as I'm aware, anyone is saying that pitbulls lack. How readily trainable an animal is is a huge factor. And so I come back to this; it's not always the owner's fault, except it kind of is.
This is purely anecdotal, but I've known quite a few vets (a parent being one), and they all have a list of breeds that they dread. If they know a Dogue De Bordeaux is coming, they break out the heavy duty muzzles. The Dog's Mind by Bruce Fogle, talks about breeds and temperament a little, but from memory his work also bears in mind the relation of physical characteristics. A simple one being the difference in exercise requirements between say a Yorkshire Terrier and a Border Collie. Collies are notorious for being destructive, but in no small part is that down to their tremendous energy levels. They need exercise and they get bored easily, and when they lack that, they tear stuff apart. That kind of lack of understanding or consideration has led to uncountable numbers of ruined sofas.