I have no horse in this race but this seems like a bad comparison. Artists typically don't charge people intermittently to come look at the painting before it's finished or invite people in to take a look when it's halfway done and go "What do you think so far?" and change it based on feedback.Of course it's an excuse, A painting might require thousands of brush strokes, many of which will do little to enlighten the impatient about the end product.
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The ultimate goal of these developers is to make money off of the users and/or tell a story they feel is best served through the porn medium. When they drop community updates, it's perfectly acceptable to judge these games as they are and in regard to where they have gone since the last update.