If your gonna use Olympic weight lifters as a example, why not just go to the top and say "Do you know any World's Strongest Man competitors doing push-ups all day."
You make note that genetics play a factor, without a doubt I agree with this, but by saying "Do you know any Olympic weight lifters that got where they are by doing push-ups all day?" You're making it seem that this is what everyone aspires to be. How many people can actually follow an Olympic weight lifters training regimen? I mean we all have to work, have sex, play tennis, have a social life, ect...
Yes, doing push-ups and sit-ups can only get you so far, but hitting the weights also has its limitations, of course the limitations is higher, but how many people here actually want to have one of the bodies on those body building magazines... I would certainly think not many. As far as where I am today, I could have as easily achieved it with weights, but since I'm not a fan of weight training, I stuck with the push-ups and sit-ups, alongside eating right, yoga, and running.