I just don't know. Nobody would like more headliners more than I would. But I think you'd have the same issue. Everyone would want to ride the new, latest and greatest ride. I shudder to think what will happen when 7DMT opens. You'll probably be limited to riding it once every six months, even with APs or multiple onsite stays (note: exaggeration for effect)
I would think Disney would know what its ride capacity is and how many people use FPs each day. The fact that Soarin' and TT are popular should not come as a surprise. Did they just think that people would be so excited to get a FP for Journey or Character Spot that they wouldn't want to go to Soarin' anymore? I would love to pull back the curtain and see what the capacity for each ride is, how many FPs and FP+s are allotted per day, and how many are actually utilized. The numbers would be very interesting.
If Disney had this tiered idea in mind from the beginning (which seems plausible, since some of the very earliest testers got tiered rides), I wonder why they didn't roll out the widespread test with the tiers. To roll it out with being able to choose any ride and then scale it back to only one headliner is a big downgrade. Most people don't like having a feature "taken away," so I don't know why they ever made picking any three an option if that wasn't part of the master plan.
The tiered system is a really tough sell for me. I just don't see how Disney can offer this as an enhancement. Under the old, free (and awesome) FP system, you could gather as many FPs per day as time permitted. You might only get one for TSMM, but for most other rides you could get two or more. You could certainly get more than three per day, and you could get them in multiple parks each day. I was willing to trade some of that for the chance to sleep in and pre-plan some days. It was fantastic to get to EPCOT at 6:00 on a Friday night the day we arrived at WDW and to be able to ride all the headliners.
But now, to give up the awesomeness of paper FP and trade it for the chance to ride only one "big" ride and at only one park and to have to go at RD to have any hope of avoiding a two-hour wait after spending ridiculous amounts of money to stay onsite? No thanks, Disney. When developing this new tiered FP+ system, "You chose...poorly." And I chose poorly when I bought that AP.