Finally people were posting some high res photos of the hat and not just cell phone photos... from this zoom in, you can see probably why they are cutting it down vs other dis-assembly methods.
Look at the panels - they appear to be bolted together.. with an insane # of bolts. The upper part of the hat appears to be purely a shell structure alone with the skin being all the support for the structure.
View attachment 79891
The white piping is likely the utility conduit for effects on the pieces.
No one wants to remove that many bolts if you don't have to... they're just ripping through it with saws and cutting pieces down in the chunks they can manage. We know the ring in the base is a big steel superstructure... it should look fun when they get further down.