B737/B757

[AirEngland]

This is my first post here. I am curious to why Boeing did not design the B737 and the B757 with a standard loading hold?

Both aircraft are fantastic machines, but I have always wondered why their holds ae bulk load only.

Could Boeing, redesign the 737 to have a standard loading hold to take containers like the A320 family. I think this would work for airlines that carry cargo on short routes.

Please tell me your thoughts, thanks.