Note, not all MOLLE is created equally. the PALS webbing (that's the technical name for the webbing strips on the pack) on some cheap packs may not be the same quality as say maxpedition packs. But good quality PALS should be strong enough for anything we are likely to put it through.
You also have arguments such as the the PALS webbing effects the waterproofness etc... But then any stitches going through the fabric will do the same, such as those for sewn on pouches...
TeeDee makes a good point about the centre of gravity. A lot of the pictures I've look at of modern "tactical" packs covered in MOLLE webbing, I can't help but think they stick out a lot at the back, which can't be comfortable.
Personally the only pockets I have on my pack are a lid pocket, and the mesh pockets on the outside. I use them for things like water bottles and my meths bottle. Oh, and the ones on the hip belt...
There is a fashion within bushcraft for forces style packs, be it the surplus LK35 packs from Sweden, or the modern Maxpedition packs. It's not for me really.
If I had a collection of packs to decide between, my first priority would be comfort, followed by weight, followed by capacity. Pockets/PALS would be near the bottom of the list of requirements.
Hope this helps.
J