I feel like Steve Jobs also fits this category if we are going to talk about people who aren't really worthy of genius title and used other people's accomplishments to reach their goals.
We all know it as the engineers who made iPhone possible.
Someone far more deserving of the title, Dennis Ritchie, died a week after Jobs' stupidity caught up with him. So much attention to Jobs who didn't really deserve it, and so little to Dennis Ritchie who made such a profound impact on the tech world and society in general.
I think Ritchie's influence while significant is overblown and not entirely positive. I am not a fan of Steve Jobs, who had many reprehensible traits, but I find it ridiculous to dismiss his genius. Frankly, I find Jobs's ability to manipulate people more impressive than Ritchie's ability to manipulate machines.
The main reason C and Unix became widespread IMHO is not because they were better than the alternatives, but rather because AT&T distributed them with source code at no cost, and their motivation for doing that was not altruistic, but rather the need to obey a judicial decree or an agreement made at the end of an anti-trust court case under which IBM and AT&T were ordered not to enter each other's markets. I.e., AT&T was prohibited from selling computer hardware and software, so when they accidentally found themselves to be owners of some software that some universities and research labs wanted to use, they gave it away.
C and Unix weren't and aren't bad, but they are overestimated in comments on this site a lot. They weren't masterpieces. The Mac was a masterpiece IMHO. Credit for the Mac goes to Xerox PARC and to Engelbart's lab at Stanford Research Institute, but also to Jobs for recognizing the value of the work and leading the first implementation of it available to a large fraction of the population.
More like ppl on this site know and respect Jobs for his talent as a revolutionary product manager-style CEO that brought us IPhone and subsequent mobile Era of computing.
We all know it as the engineers who made iPhone possible.