Ah, the overhead bins! Why do aircraft makers not understand that pax need to store their enormous 25 kg suitcases in the carry-on overhead storage?

Especially in Knoteetingham where the average pax has 2 carry-ons of this proportion?
And why insist that they "keep seat belts on till the engines have stopped", when everyone knows that they can make the gate before the aircraft, and the baggage belt before their luggage?