Its not the only way, its one of the ways... Not always your team has perfect composition, and if that is so, dotting sometimes helps to save the game,if oposite team is good, they will win anyways.
Past 2 weeks i see lots of heals on imp side in WZs (2-4 in one game), they make their team practicaly unkillable (3 heals + 5 dps jugs is immortal combination),on our side its good if we have atleast one heal, so thats were dots give atleast some chance.
Im fine with changes, yes game will be more intense, but belive me lots of other balance issues will show up, and the dotting isnt the worst of them The better fix would be if dots expire after dotters death.