Some QRHs use MEA instead of 10.000 or MSA. Others...consider at least FL130 "as a the top" because it is the FL or altitude in which you can avoid an automatic deployed of masks and also be able to breath and save fuel for a while...
...And just to add to the mix on some types it's 15000' or MSA, whichever higher....
As LSM has said:
its just something as simple as maximising range once you've descending to a survivable altitude. Of course that doesn't matter over the middle of Europe but, mid Atlantic it might make a difference