The culture of purely finished work has certainly led to some drawbacks from what I've seen: the pressure to only post finished work, and also artists being unable to establish a process since the end result doesn't show the steps it takes to get there. Finished work is nice to look at, but it hides the parts that are most relevant to other artists; that is, how to actually bring the artwork from start to finish.
To be fair, though, there are some artists who can sketch but cannot polish their work, and there are some artists who can only seem to polish but never sketch. Maybe the diet should vary between artists, but I don't know for certain.
The culture of purely finished work has certainly led to some drawbacks from what I've seen: the pressure to only post finished work, and also artists being unable to establish a process since the end result doesn't show the steps it takes to get there. Finished work is nice to look at, but it hides the parts that are most relevant to other artists; that is, how to actually bring the artwork from start to finish.
To be fair, though, there are some artists who can sketch but cannot polish their work, and there are some artists who can only seem to polish but never sketch. Maybe the diet should vary between artists, but I don't know for certain.