Making things, aka being an engineer, is an art and a craft that takes time to master. Even if you work in software, there are no quick routes to riches. Zuckerberg may have been young when he hit it big, but he had been programming for a long time. I can't imagine that physical engineering takes less time to master (but hey, I don't really know.)
My point is "traditional product-making firms" probably fail to offer fast-track positions because there is no fast track to being good at traditional product making.
I think there is a difference between the engineers making the products and the people marketing and managing the companies. I acknowledge that it is not likely that the engineer will add huge value without substantial time to master his field, but I do feel that a bright creative business person could add substantial value. Unfortunately, I feel that they are lured away by the finance riches, so we never are able to see their impact.
My point is "traditional product-making firms" probably fail to offer fast-track positions because there is no fast track to being good at traditional product making.