But why should they? all his attacks have noticeable startup time, are laggy, are telegraphed based on spacing, and can generally be beaten out by just using fast attacks, they only thing to keep in mind about DK is, he can destroy a player for using shield, roll, ect. and for approaching with something unsafe. Hes like ganon except he trades even more seemingly "scary" power for some speed and range. The only viable characters that should fear him are snake, because he isn't mobile or fast enough to abuse DK's lack of speed, and lucario, because a good DK won't let lucario live long enough to become a powerhouse, mainly due to how DK gimps lucario exceptionally well and outspaces lucario, whom, without his spacing game, is not a hard to fight character.
edit: i like Yaaay's qoute, respect the power, but never fear it