You by all means do not offend me as there are different ways to mount the camper and there are many different abilities of the person to accept or fight the process. I have had 3 FWC and all of them have been bolted through the floor. For me it has never been a PITA process. The latest one we bought is a 2015 FWC Hawk flatbed. It has 6 bolts through the floor.
I did need to separate the camper from the truck to do some electrical wiring. As I have done with the other campers I use a sharpie and make a series of reference lines bed to camper. Upon getting the remount close, you don't need to be perfect just get the reference lines somewhat close back. Don't drop full weight down and that allows bolts to be dropped from the inside. If some are off a little just nudge the camper that direction will drop into place.
You ask why do it this way? I accept this is the way I want it and have extreme patience for going slow. It is not that any way is better or you have to do it this way and your way is wrong, it is more up to who is on the other end of the tool doing the task.