I'll preface this by saying that my setup is far from high end, but I don't think that statement sounds reasonable. Every headphone has a particular frequency response, and every headphone has some sort of imbalance somewhere in that response. Additionally, every human ear is a little different and exerts its own "natural" equalization on the sound. Then you get into the murky realm of sound signature preferences. What this amounts to, in my book, is that every headphone, no matter how "good" or "high end" can benefit from equalization. It doesn't have to necessarily be alot - maybe your sound preferences just match up really well with what you have - but for all practical purposes I feel that all headphones benefit from equalization, even if it is very modest.
Edit: I'll add that when you become older and start losing high frequency perception, an EQ is no longer a tweak to make something sound better, it becomes absolutely essential in order to properly hear your music.
Highlighted sections make total sense to me. I like to hear everything in the music, highs, mids and lows....without any of them drowning out the rest. Taking into account the fact that my different headphones do not sound the same, and that I have lost some of that high frequency perception, and an EQ is very useful for me, used sparingly.