The biggest reason for this are the players that actively build fortifications like wire directly in front of a rally point.
Several times yesterday, I had the front of the objective fortified, and had a rally close by behind, and set my squad to control the hallway. The teammate literally built wire on both sides of my AI and filled the hallway from my rally point to the objective with wire.
Definitely done on purpose to troll, but I had no way to know who it was in order to report them.
(Also, could a moderator/helper actually inform me if those reports are taken seriously?)