My argument against doing this is it's hard to get into NY/Boston/Chicago for a 2:18 type runner. They aren't going to get into the elite field, and they probably have to pay the massive entry fee as well, and pay their hotel and airfare. A 2:17/2:18 type runner could go to a mid level marathon and get a free hotel room, and possibly even some prize money around $1k.
But the McKirdy 'time trial' was no different from Chicago or Berlin or any other race. All races people show up trying to run fast, and there are a few different pace groups. There were pacers at Chicago and Berlin doing around 2:01 pace and then further back around 2:06/2:07 and probably others. If Merber is singling out the McKirdy race, then that makes no sense to me. Most races have pacers, and people seek out the flattest courses to hit the standard. It's why Fauble went to Berlin, flat course and people to run with trying to hit a fast time.