But focus and attention span are skills that need to be practiced to be developed. If you never get that practice, the scope of problems you're able to solve shrinks substantially, because a lot of big problems need sustained attention to make a real dent in. Coming in from a lateral angle with ideas from other areas are great, and a lot of problems are solved that way, but you need to be immersed in the problem space at some point before you get that stroke of insight.
You need to be able to sustain attention, though, and that takes practice.