More often than not, the ones who suggest a two-park HHN are ones who never went to 14 and had to make the long trek through the parks. Conversely, the ones who did experience 14 aren't really clamoring to have a two-park layout. For the amount of folks who gripe about the walk to and from the parade warehouses, the buyer's remorse would be instant for a backstage trek.
I'll also add that you're not really alleviating crowds if you're putting them into smaller pathways.