I think it's because unlike F1, we don't have 7 speed gearboxes. The normal rpm range of an F1 engine is a lot narrower than ours. With the current fuel flow and rpm limits (and 7 speeds) in F1, they only need to make good power between 10 and about 13k and even then they have hybrid power to boost the bottom. We need to make good power from 20k all the way to 50k. Long strokes seem to be able to still make decent 50k power but are much better in that 20-30k range.