I never called it lucrative...but if you get economies of scale involved, it can easily get that way. Then there are breeders that have made their name already, have a respected name and reputation for producing quality dogs, and can ask for higher prices even when they breed untitled bitches.
In that chart...although good...some of the costs aren't there every litter. So...the health testing is done once for each dog. If you have 5-6 litters from each bitch, you've already got $2500 more. Flying in a daughter in order to watch pups? Not necessary. Taking 5 days off of work...if you don't work in the first place, you can't really consider the lost wages a cost of whelping a litter.
Some of the "other costs" that she claims to have...you'd have those even if you didn't breed. So in all technicality you're actually getting reimbursed for some costs that normal pet owners have anyways. Dog food, fencing, dog equipment. The only way to "avoid" those costs is to not have dogs in the first place.
Here's how I look at a close breeder friend of mine...they're going to train and title their dogs anyways. Schutzhund is their hobby, they want to do it in the same way that I want to play golf on the weekends. So...they're going to spend that money no matter what on the hobby, breeding the dogs afterwards (once they've proven their worth) is kind of a reimbursement for those costs, so in a sense, they're "coming out on top" as all things being equal, those are sunk costs anyways and the breeding money just supports/offsets some of the costs of their hobby.