In 'classical' music, must a piece be difficult to have merit?

I was reading wiki page on Bartok's 'For Children'. For those unfamiliar, it's a collection of intermediate level pieces intended for students to play, and children to enjoy. The page had a comment that some concert pianists like Zoltan Kocsis are including some of the pieces in their performance 'for their musical value - in spite of their pedalogical origins'.

Damn straight. Good music is good music. It saddens me to think music might (and probably is) be excluded from public concert performance merely because its too 'easy' to play.

via International Skeptics Forum http://ift.tt/1XBurJC