Why will it get rid of those types of matchups though? Once you get back to 64 after the first set of games you'll be right back where we are now, right?
True. Are we to assume that all of those mid major teams will advance out of the 1st round? I would guess that at least 50% of the mid major schools will get bounced in the 1st round. Thus there will be less of a presence and a much smaller chance that any of these teams will advance past the 2nd round. This will effectively kill the reason that so many people tune in for the first weekend of the tournament.
I religiously watch the 1st round games the first 2 days because it is exciting and has compelling matchups. There isn't anything compelling about Robert Morris playing Northwestern in the 1st round. What is compelling is watching Robert Morris take #2 seed Villanova down to the final seconds of OT in the 1st round. So Northwestern in this scenario beat Robert Morris and now we have Northwestern vs. Villanova.... Is there any compelling story there? Is there any buzz? You couldn't pay me to watch that game. If Northwestern wins is it a win to celebrate? Does it create headlines? Nobody would even care.