One of the things I learned from our Alaska trip a couple of weeks ago, the port areas are very small, and sometimes one ship has to wait for another one to leave before they can dock there. Thus, the decreased time in port. The port that we had the least amount of time in was Ketchikan, and that turned out to be a huge disappointment, because I could have spent forever there. It is truly charming.
Our cruise DID do the Inside Passage on the way up the coast. I was on the Norwegian Pearl. We didn't do it on the way back, and guaranteed, there is absolutely NOTHING to see that way...except a few other boats.
I realize that if you've never seen it, you won't know what you're missing.....BUT.....you can pretty much guess what you're missing. It would be like taking a Panama Canal cruise and being locked in an inside cabin where you didn't get to enjoy the beauty & wonder of it.
Of course you will have plenty of activities on your sea days, as we did also, and yes, there is the magical Disney experience, which will still make your cruise fantastic. But it's a shame to have to miss the Inside Passage.
The reason that they probably are not doing it, probably has more to do with the impact on the environment than anything else. Alaska and Canada are very strict about keeping their waters clean and protected, and since
DCL is new to this itinerary, they probably won't have "first pick" at the Inside Passage for a long, long time...if ever. Not to mention that until this past year, Disney came in pretty low in the ratings of how environmentally friendly they were.
Anyway.....in order to make the most of your time in the ports, plan your excursions wisely. Choose excursions that do a variety/combination of things. In Juneau, we did a tour that combined taking a small boat out whale watching (tons of whales!) and then a nice bus to Mendenhall Glacier...so we got to see the town, the whales and the glacier and still had time to shop.
Skagway, we'd planned on doing what everyone else was doing....taking the Yukon Pass Railway up and back. More thought made us realize we'd spend all day seeing the same exact thing, so we chose a tour that took us to a famous old saloon and brothel for a tour before they opened to the public, then a bus ride (there were only 11 of us total on the tour) up the Yukon Pass, with stops for pictures along the way, and then met up with the train for the ride back down.
In Ketchikan, since our time was limited, our son took the "Deadliest Catch" Crab Fisherman's tour, while my husband and I wandered all through town, took some back trails, and got to know the town a little better than we would have.
With careful planning, the shorter days in port will work out just fine.