I, too, miss the diversity of the stores and merchandise (ahem...in the parks as well). I think that has had a negative effect on Downtown Disney, and therefore PI. And I understand what everyone has said about the effect of removing the gates. My first trips to WDW were in the early 90s, and we went to PI almost every night. We weren't much for the clubs, but we enjoyed the atmosphere at night. We were fine with just buying a drink and strolling. Perhaps we were part of the downfall...we didn't spend enough money.
But I have a question: what, if anything, do you think the effect of the Dining Plan and/or free dining has been on DTD and PI?
I'm not too familiar with the dining plan, except that when I went on a solo trip in 2009, almost every food service cast member was incredulous that I wasn't on the dining plan. But has the dining plan kept people in the parks and drained some of the flow from DTD? Just curious.
Oh, and an idea for improvement. Now that Characters in Flight might be flying the coop, perhaps Disney should invest in one of those fancy ferris wheels such as the London Eye. I would love a safe, air conditioned sky-high view of WDW.