At least part of the reason not to credit individual engineers is that it damages the myth of the genius CEO. Ask most people who invented the iphone, they will not say "it was the work of hundreds of people at a dozen companies inside and outside Apple", they'll say "Steve Jobs".
That is different though. Steve Jobs never claimed credit himself. As a matter of fact his autograph are extremely rare;
"Steve politely declined several times, stating that everything at Apple was a group effort, so he didn’t like to sign and take credit for everything. " [1]
And with every Keynote Steve will thank all teams who has been working nights and days, often using the phase "separated from their families". And constant and consistently reminding everyone that "We, at Apple." Not "Me, Steve Jobs".
I remember some made the observation Elon Musk is more about selling himself than Tesla or SpaceX. Steve Jobs is more about selling Apple himself.
But at the same time let's admit it, Apple without Steve Jobs is just different. There is no one to keep the balance between everyone. Jony, Eddy, Tim, Phill, Scott Forstall and lots of others. Steve often likes to refer Apple as the Beatles, where the whole is greater than sum of its parts, and they kept everyone's flaws in check.
