A Serious Draft Question

[OSUfan]

 Ok, so I know that many Bengals fan seem to be opposed to trading down yet according to many sources that grade players for a living there are only anywhere from 17 to 20 prospects in the class of '23 that have garnered a 1st round grade. Given this information why would someone be opposed to trading down and acquiring capital over drafting a player in the 1st round that does not have a 1st round grade but pay them 1st round money?