I used to play Lucario against my brother on a fairly regular basis, and while my brother has never called Lucario cheap, he had become annoyed with how projectile spammy/campy I end up being, forcing him to approach by using Aura Sphere, then batting him away with aerials.
My brother is a good player, and he adapted, managing to get past my style of Lucario play...*cough*by counterpicking R.O.B.*cough*.
Suddenly, it was my turn to adapt my playstyle, since how I was playing Lucario didn't work very well. Haven't played against his R.O.B. terribly recently though, but I'm sure it'd still hurt pretty badly.
Characters considered "cheap" are by no means unbeatable, one just merely needs to be able to adapt (although, the ones that throw the word "cheap" around tend to be the ones that can't adapt). Sometimes it just means extra care needs to be taken against them (or you can counterpick them, hehe).