Fair point!As discussed in other threads, there is an element of risk though. If your bolts should fail when being removed you end up in a position where LR won't help you and a new rack is most likely required!
So rather than a "no brainer" it also depends on how your luck runs
If this wasn't a risk I reckon LR would be changing bolts...
The risk element could be reduced (but not eliminated) by LR specifying a maximum undo torque at which point you abort (although maybe there isn't space to use a torque wrench?), a descent mechanic will know with "feel" anyway.
Bottom line is JLR bean counters have more sway than customer relations.
If the desire was there then a procedure could be put in place, replace the bolts where possible, if a bolt snaps above a set value then you've saved it happening further down the road - on the road. And as @makkan00 intimates, in the engineering world the rack is still recoverable even if snapped, it just means the customer is more inconvenienced (but not as much as a failure on road). Of course also greater expense for JLR, but that will get them in the end anyway.
But until JLR is hit by sufficient litigation there just isn't the will.