True, but the best engineers are the ones that can adapt to new skillsets quickly. For example, I'm willing to bet that 99% of the most successful iOS develope

True, but the best engineers are the ones that can adapt to new skillsets quickly. For example, I'm willing to bet that 99% of the most successful iOS developers had not written a line of Objective-C until 3 years ago. Apple simply provided an opportunity and they embraced it, learning the skills they need to adapt.