No need to start a heated debate
People will use what they like.
I just argued that external frames had the disadvantage that the balance point is moved further back. This is caused by the empty space between the frame and the pack itself. Internal frame packs have the main compartment between the support (if it is a pack with support at all), and thus getting a more close fit, and stable pack.
I heard the same argument from backpackers that were active from back in the 60s when the first external frame packs came. And they really don't miss them
I know that people in here treasure 'old stuff' a lot, so perhaps it's pointless arguing against something that was "good enough for my grandad"