Takai, are you kidding? like, have you read the last 3 posts before yours? - feels a bit redundant because others pointed it out while i was posting
studying popular and attractive works its a great way to start, thats why nearly everyone can spot the SD3 grass, most often drawn from tsugumo's tutorial, or, less commonly, a knockoff tutorial also on zoggles, but also, occasionally, from direct observation of screenshots. (did i really just say direct observation of screenshots? ewwwwwwww....direct observation comes from life! remember this! you will learn more about spriting grass from looking outside than you will from studying other artist's interpretations of the same object)
there is nothing wrong with this style of learning, except for the fact that you lose the creative credit that comes with discovering your own methods.
many people dont worry about this with something like grass tiles (because despite the fact that there are so many possibilities, its still hard to come up with a style that doesnt look like something thats already been done several times by someone else).
This however is in general a creative/artistic forum, even though it can be geared towards specific styles, so in general, copies and interpretations are viewed as beginer-level work which will help the artist to blossom into the intermediate realm of cautious experimentation driven by the imagination, and eventually to advanced realm of complete creative freedom and exploration that is both an amalgamation and complete rejection of the art to which they have been exposed to. A select few, the masters, surpass even this level of creation and define existence as themselves, therby proving that they themsleves exist as independant sources of creative material for others to draw from.
So like i said, studying the masters is fine, it's where most people begin, but the creative process is one that builds independance, not reliance, which is why emulation is often plagued by the idea that it is 'beneath' certain levels of art and creativity.