That's why I travel with a small laptop bag. It holds any personal items I might need to access during the flight, and I can squeeze it into most any remaining gap in the bin over my seat, or even under the seat in a pinch. My rollaboard goes wheels-first wherever I find room (spare the flames, it's of legal size) , and often gets gate-checked, but it doesn't matter since the stuff I might need is close to hand.

Mr. HuffyPants had 2 bags so could've done the same, or could've politely explained his desperate need to keep his entire luggage ensemble close at hand, and also should've offered to relocate your bag (it was for his sole benefit). You would've been under no obligation to accept.