This is my biggest annoyance with HAL. With status on other airlines you can book preferred seating or exit rows online as soon as the reservation is made and readily change anytime a better seat comes open. And with experience you can be pretty assured of getting a seat with comfortable legroom and great bathroom access.
Platinum Status on HAL gives you nothing but miles and early boarding. You still have to sit in a seat with 31 inch pitch next to a Sumo Wrestler and wear 2 blankets to survive the 40 deg F cabin temperature.
Perry