I love that your justification is that you went last year...I live five minutes from property, so if your basing your statement on then then...well...
I disagree that DHS has a reputation for being a half-day park. Perhaps if you're a local, or come regularly sure, but Hollywood Studios is a show-based park, and shows tend to take up more time than rides.
Consider: A family of four arrives at 9:00am (Dad 40s, Mom 40s, Daughter 11, Son 7) and makes a beeline for Toy Story Midway Mania. They get in line, which is still short first thing in the morning, and LOVE the ride so they decide to get a FASTPASS for later, by this time FASTPASSES are probably distributing for say...2:00-3:00pm.
Son is just old enough to want to try Tower of Terror and Rockin' Roller coaster this year, so that's the families next stop. they ride Tower of Terror, but the line for Rockin' has already gotten a bit long, so they decide to come back later to grab a FASTPASS. By this time, it's say 9:45-10:00, And this family has on their agenda Lights, Motors, Action, Star Tours, Muppetvision, The Phineas and Ferb Greet, Great Movie Ride, Indiana Jones Epic Stunt Spectacular, the American Idol Experience, Beauty and the Beast: Live on Stage. All of those things will take them AT LEAST Five/Six hours, so it's perhaps 3:00/4:00 in the Afternoon, Time for Toy Story Fastpasses, and somewhere in there they also grabbed Rockin' Fastpasses so let's add that in and about 45 minutes for lunch as well, so it is probably AT LEAST 6:00/7:00pm by now. The family decides to have dinner, Ride Tower of Terror A second time, and round out their day with Fantasmic!
Full day.
Now as far as the parks being "In Shape" to use your words, What about Hollywood Studios is not in shape that I haven't already mentioned. I said that GMR and Backlot were it's biggest problems (And I would personally like a Fantasmic Upgrade, but that's never gonna happen) so what else exactly are you referring to? If you mean adding new rides, well I said that too, They need a new ride on the Left side of the park desperately to spread crowds from Rockin' and Toy Story.
Lots of Magic Kingdom is simply starting to age, and like I said the park is flawed from a crowd flow and congestion standpoint, particularly in the evenings around parades and fireworks. I would love to hear what else you have to say, but I don't see how you can argue that specific point.