As for the original question- nice, comparing professionals to hobbyists and expecting the latter to always be as good as the former.

For programs like Maya, there's a fairly steep learning curve involved. It takes a while to get a realistic render of anything more than, say, a simple cube. I've worked a bit with Maya, 3DSMAX, and Blender- they're not exactly user-friendly, but they are designed for professionals. I forget where I saw it, but I believe Blender was said to have a two-month learning curve before the average CG artist would be proficient enough to use it in a production environment.

Whereas with Poser, you can render your first "Vicki-in-a-Temple-with-a-Sword" an hour after installing the program for the first time. (Or even faster if she's naked.) Many people, happy with that, don't go further.

Poser can do near-photorealistic renders, but it takes a lot of time and experimentation to get it right.