I am of the opinion that cats are like people -- they each have their own personality. Some are lap cats, some are not.
I had Comere (RB) for nearly 18 years and he was a great big mushy lap cat his whole life. Everyone that met him laughed at what a mushpot he was. You petted him once he'd be your buddy for life... not only up on your lap, but your chest and as close to your face as he could get (and he was a HUGE cat, so it was quite the sight!)
He was always looking for a soft lap to site on, or to be curled up to you as close as he could get.
Cosmo, on the other hand, is a friendly guy but not in the "I'm gonna jump in your lap" kinda way. He likes to plop on the floor just out of arms length and roll on his back for you. He wants you to come to HIM for a good petting. He does the same thing when he jumps into bed with me... plops and rolls, just out of arms lengths and starts kneading his little paws waiting for a pet, belly rub or chin scratch... on HIS terms (brat! LOL) -- He's only jumped on my lap a couple of times and once when he was scared to death of the vaccuum.
He also loves to give head-butts and kisses (little licks) if he's up at your level or you're down at his. Of course, he's also still very young (the vet guessed about a year old) and is more interested in playing than just about anything else.
My mom's cat, well she liked a good butt scratch and isn't much of a lap cat at all, though she's getting to be more of one the older she gets (she's about 15 now). Most of her life though, she's the type to sit near you but not on you. And she likes to curl up under the covers with my mom at night
I really do think they are like people... some people like to give and get hugs and are more openly affectionate than others... same with kitties