When I need to carry my fairly heavy laptop, and have any appreciable amount of walking/transit, a shoulder bag simply doesnt cut it anymore.
Im happy to have made the recent switch to backpack. Though for my personal vanity it's a more exotic-but-low-key from a French "designer", rather than the denier nylon with 50 straps hanging off.
Around here in the EU its not a faux paux. I see them everywhere.