2013's is one of the greatest HHN houses of all time. It's the reason they brought it back (among other things). But the house itself, while great, wasn't the reason it was exceptionally well received. The cast of a house is what makes a great house perfect. And 2013's casts were INTO there roles. The house just worked.
This year, it's just not the same. They removed scares, fog and strobe effects as mentioned earlier, and the casts don't seem as energetic as 2013's. The new wolves look better, but that's literally the only positive change to the house imo. On top of it only being 2 years old, I honestly think this was a bad move. And I was one of the people looking forward to experiencing this house again. This version has the chance to ruin the original's legacy, as newcomers will see a house that isn't as spectacular as everyone has hyped it up to be the last 2 years. Shame.
I agree with Brian, the fact that this year's lineup is stronger than 23's also plays a factor in it's reception this year. However, AWiL 2013 is now my #3 favorite house of all time, knocked down from 2 by M&M. I think FvJ, Insidious and Body Collectors are all better than this year's version, but not 2013's. So yes, having a weaker lineup in 2013 helped with AWiL's popularity, but it doesn't negate the fact that the house was phenomenal.