I'm still trying to figure out why they got rid of the observation tower at Gettysburg. I thought the "aerial" view really helped in understanding the battle.
I liked the Gettysburg Observation Tower too, and for the same reasons. My understanding is that the tower originally stood on private land, and that the land was eventually purchased and incorporated into the Park. It fell victim to its own age and the Battlefield Commissions desire to restore the field to its original 'Look'. Eventually, all the tree lines and fields are going to be brought back so that the Tour Guides don't have to say, "now in 1863 this open field was a wood lot...".