You're right in a sense, but not always the case. I remember a time when Pirates of the Caribbean was always a packed queue... and then somewhere along the way it became a ride that you could literally walk onto all the time. Then came the PC upgrades, sound upgrades, so on so forth and it's as popular as it ever was again.
The treehouse... yah, I wonder what it would take for that attraction to recieve the breath of new life. Though I'm sure they could have spent a lot less to fix it up than to do it all over. Did the treehouse really affect the guest count by that much?
In the long run... it does nothing to the overall guest experience.