sorry but I am just a dumb ppl - but as far as I am concerned , i consider ATCO's to be professional enough to keep me away from becoming a major contributor to an aluminium rainshower , legal or not if they request below 2000' i'm sure not going to argue unless I can see cumulus granitus or some other obstruction in the way
when I would politely suggest i might initiate a climb. i cannot see the reason people are complaining , c'mon people we are all trying to fly safely in an area which is becoming busier with commercial traffic, anything that keeps all pilots and pax safe is ok by me