Raising cats as dogs

I still haven't gotten the critters to bark at the postman, but here's an oddity: I keep reading that one should never try to give a cat a belly rub, 'cause that's strictly a dog thing.  And yet:  all three of the now-very-overgrown kittens solicit, and seem to appreciate, belly rubs and skritches.  Even when administered with a foot, or at dog-level intensity.  (Though I haven't gotten the standard canine hind-leg-jerking response from any of them.)

Addenda, as I click random links on that site:

Here: "Cats can’t open kibble bags or cans of food, and they can’t hop in the refrigerator and help themselves to leftovers."  Um.  Leave a bag of Trader Joes's kibble on the floor around here, and it'll soon be torn open.  And, while I haven't, yet, found the refrigerator inexplicably open, the critters certainly have learned to open kitchen cabinets.

Here: "...even a few ounces of chocolate can be enough to cause illness in a small dog..."  A few ounces is a lot of chocolate!  On a bad day, an ounce of chocolate will make me sick, never mind a small dog.