In construction terms, hotels are easy to build. They're essentially identical rectangular boxes stacked on each other. The public spaces will be customized, but it's still not difficult in terms of the actual work.
Given that this is a high-rise building, there will (probably) only be a couple of Central Florida companies able to build the structure. But, once the building is up, the list of sub-contractors who can finish the inside will be lengthy. Installing walls, plumbing, and electrical for hotel rooms isn't specialized work. The same fact holds for things like the restaurants and meeting spaces for this hotel.
The reason why it seems to take forever for Disney to build attractions is that those are one-of-a-kind structures. (Maybe two-of-a-kind if it's a clone from another park...but the actual workers wouldn't be imported to build.) Additionally, attractions must be built with care to ensure guests don't get hurt once operational. The likelihood of guest injury from a poorly-installed sink is low. The same can't be said for a poorly-installed support beam for a roller coaster track (as an example).
For what it's worth: When I worked at Walt Disney World, I asked a theme park operations manager why attractions at
Disneyland seemed to be built quicker than in Florida. She said that was due to the fact that there are more companies in Southern California with the specialized ability to build the unique structures when compared to Central Florida. In theory makes sense. Southern California has almost 24 million people; Central Florida has about 8 million.