Your hyperbole aside, I frankly think that either having a one-day, nationwide, closed primary or simply choosing the nominee at the convention are both better alternatives than what we have now, which is to have the primary season strung out over five money-wasting months and have a large share of the people voting end up wasting their vote because their candidate drops out early, etc. etc.
So you are for a fractured free-for-all topsy-turvy convention? Even Obama could not have hoped and prayed for this much of luck.
It's unlikely Reagan would have ever been nominated had either of those scenarios been in effect.