When you're trying to sell someone on DVC, this is another differentiator for the family that might otherwise stay in a moderate resort normally. It's easier to sell DVC right now to someone who already wants the deluxe resorts. The price comparison is trickier with the lower level resorts.
Now you have a real reason to maybe pay up a little bit more. There really wasn't one in the past. Not unless you were someone who traveled more than once a year already and could benefit from the AP's.
At what they're charging for Deluxe rooms (and apparently getting it), I understand this perk, but I don't have to like it. I wouldn't mind paying extra for this perk as a value resort customer this time around.
You can, there will be a lot of after hours parties in the future.
WDW is evolving to a model in which one can pay a lot (entrance ticket) and suffer in long lines or pay even more (Premier Access, Deluxe resorts, ticketed events) and skip some of the lines.