This is what happens when Riot listens to the lower elos opinions on assassins. They're always complaining about the assassin killing them with "no counterplay," because someone jumps on them and throws their burst in their face, they die, and whine about it. They don't have the capacity to realize an assassins counterplay isn't MEANT to be about after they get on top of you, it's about not letting them. Assassins counterplay is pretty much 80% positioning and 20% playmaking.
Thus, ekko was born, a champion that wasn't feast or famine because he had utility, and almost a complete lack of an ability to ACTUALLY assassinate a target. Thus, people started playing him as a tank/bruiser because an assassins JOB is to kill someone, if they can't do that effectively, then there is no point in playing them as an assassin.
To chalk it up, the boards whine about assassins being able to kill them, they complain about their feast or famine nature, Riot tries to listen, makes ekko, and SURPRISE SURPRISE, he's not played as an assassin.