For chess players who are not sophisticated enough, one of the leading aesthetic criteria is probably the value of the offered piece. An experienced player will primarily value the originality and purity of the idea.  It happens that a key to a position is a seemingly discreet move. Situations like these have always impressed me the most.

Firstly, by their mystery: why does one of several apparently equivalent moves turn out to be much stronger than the others? Secondly, a modest move can radically change a well-established position assessment and even change the outcome of the game straight away.  Where did the idea for this kind of work come from? 

There are two reasons. 

Firstly, while browsing chess literature, I have not found a publication focusing on quiet moves, as most often, only three to eight examples are given. Secondly, we have always felt sorry for a person who cannot see beauty, for example of mountains (as these are just rocks) or architecture (as the Eiffel Tower is just iron), etc. The same applies to a large group of chess players, who value only the size of the piece they offered or the victory. However, one can lose a game and feel satisfaction because, for example, they found a stunning quiet move in their game.