Get with the program guys.

Discos have been like this since 2004. Great design; monocoque body on a ladder frame. Body comes off easily it was deigned to do so, the connectors are made to be undone.
Remember most things can be done with the body on but as with most modern vehicles there is not much room under the bonnet. Some vehicles need the engine out to change turbos. Body off on these vehicles is easier.
Dealers make a decision as to what will be quicker and easier and in some cases where the LR manual says body off job dealers have found a way to do the job without.