First off (and this is unrelated to the casual vs competitive argument), this thread does not deserve to be stickied. Yes, the article you referenced does make a couple of good points and is incredibly well-written, but it's not only been referenced countless times in the past but it only refutes a couple of many typical casual arguments. It is the not the "end all be all" to this debate.
Though what I normally find more important than the argument that the article posed (when applied to Smash's advanced techniques specifically) is the fact that little to no advanced techs are naturally advantageous to anyone.
For example, wavedashing will not automatically make you a better player if you can only perform the technique alone. Anyone can press the buttons/joystick in the order needed to perform the technique; you need to know how to use the technique, then practice putting it to that use in order for the technique for it to be the least bit effective. It's essentially the same thing as a basic technique or attack in that sense (you need to know how to use it with the proper spacing in order for it to be any useful). Granted, advanced techniques are harder to learn and perform than basic techniques, though the phrase "advanced technique" implies that they'd be...well, advanced.
That being said, advanced techniques don't hurt anyone. They're not "cheap," and they add tremendous depth to Smash.