I dont regard myself as an 'artist'  so I use Poser because its fairly technical in creating a scene. That said you do need to learn about composition and lighting to make a 'good' picture 'great'. Being able to paint inside the lines also helps in making your own textures even if its a small change to something purchased.

I often get to a stage of saying, this is as close as I can get to my idea with the models and textures I have, where those with better skills could get exactly what they want.  That may be a completely valid point at CG Society but I know several modellers who dont texture, and several texture artists who dont model so a Poser user who does a bit of everything is slightly ahead when working by himself.