Let me preface this by saying that AK is a beautiful park...just wonderful attention to detail; however, it is also the park we're most likely to cut. I'd also like to note that this really comes down to you and your family. There are many who love it and could never dream of skipping it- and their reasons are all justfied for them/their families.
For our family, there is very little for our kids to ride, the details are lost on them, and both DH and the kids don't handle stationary lines for shows very well. i.e. a 30 min wait in a moving line is far more enjoyable than standing around for 30 min waiting for show seating to open up. And while I know AK is well beyond a zoo, our local zoo is pretty darn excellent- especially with the larger animals (like the big cats), so the kids are often left wanting more when we're doing animal things at AK.
Moral of the story, if you think your time would be enjoyed more in a different park...I think you know what to do. Personally, I'd rather have an extra Epcot or MK day vs. going to AK. I don't even think it's worth the extra cost of a 1-day hopper to split between DHS and AK, but once again, that's just me.