The people who weren’t controlling can’t tell you why the controller did what he did, nor can they be assured that your setup is even accurate. Just PM the controller and ask, instead of airing your complaint in public.
As Approach, we do things for any number of reasons. It’s not always apparent on the map. Personally, the biggest problem I have with pilots, far and away, is that they wait until the last possible second to descend. (And, for example, don’t even know how far away they are. If you were going by how much distance you had left on your FP, that wouldn’t be accurate. It would be an overestimate because of the twists and turns in it. Plus, the distance from the tower isn’t what we’re worried about.)
Anyway, when someone calls in high, I just stick them in a hold. I’m not going to waste time coaxing them to get down. Perhaps this particular controller sends you on a long route to lose altitude. Perhaps it was something else entirely, we don’t know. Because we weren’t the contoller.