It's actually the inverse cone the causes the KKM to drop high rpm air flow. So another filter with that same attribute would suffer from the same design flaw.
Also a tapered filter is better for fitment and getting airflow across the entire surface area. In order to use a non-tapered filter the diameter (and likely length) would need to be much smaller in order for it to fit. Smaller = less effective filter area = less cfm flow ability.
(For those that bring this up) Putting it down by the radiator wash and hot tranny IS NOT an option for good performance IMO.
