I'm for keeping it separate, but the reason is probably to cut down on the cost. I am in favor of that, but like others have said, I don't want everyone I need to show my DL to know about my CHL. If the reason is to help cut down on the number of people that forget to display their license and inform a LEO requesting ID, I don't buy that. If they were worried about it they would not have removed the penalty for not doing so or just lowered it to a fine.
"Immediate necessity makes many things convenient, which if continued would grow into oppressions." Thomas Paine, 1776
"In this present crisis, government is not the solution to our problem; government is the problem." - Ronald Reagan, January 20, 1981, Inaugural Address