Referencing course handicaps to par makes sense for several reasons.
First, it is how we actually use and think about handicaps. When we post net scores for our tournaments we subtract our handicap from what we shot to get our net. We think of that net score as over or under par even though that wasn’t technically correct under the old system. (It was really over or under the course rating, not par.) Now course handicap actually is strokes away from par. We will be correct when we subtract our handicap from our score and think of that as how we shot compared to par.
Second, things will be easier when we compete against one another from different tees. When everyone competing is playing from the same set of tees, it makes no difference what the course rating of those tees is because it is the same for all competitors. But when we were using different tees under the old system, the varying course ratings confused players and required us to adjust handicaps.
If we wanted to have a low net, full handicap match between four people with each playing from different tees we now can do it much more easily. Imagine we put a foursome together composed of men and women with one player on the blues, one on the whites, one on the golds, and one on the reds. We could do this under the old system, but we would have needed to figure out which set of tees was our reference standard and adjust everyone’s handicap to those tees. I’ve been through those debates, and they aren’t a lot of fun.
Under the new system we just use each player’s course handicap from the tees they are using. We’re ready to go. No debate or adjustment is required as long as par is the same for all sets of tees because everyone’s handicap is already referenced to par.