in a cartoon group to which I belong, folks sometimes post poser renders. they are usually ignored. when the poser users have complained about this, sometimes the response is "I don't know enuff about 3D rendering to comment on it". as the artists in said group mostly draw cartoons using pencils, pen/ink, and/or painter/photoshop, it's a passive-aggressive way of implying they think the renders are unappealing, compared to cartoons drawn by hand. on the other hand, I've also seen "reaction formation" here and elsewhere, when a non-poser user criticises a poser render. it's a defence mechanism of redirecting the criticism away from the target and towards the source. my only suggestion is to be kind and fair in one's criticism. if one isn't an expert, tell 'em what one likes about the image, and be as diplomatic as possible about pointing out any "flaws". similarly, folks who are at the receiving end of said criticism should be patient with their critics, and try to make the best of it.