Can't Shallow DOF Be 'Created' (Well) in PhotoShop?

I'm not all that up on this discussion, as I haven't shot with a 'real' camera in years, so I never gave DOF a 2nd thought.

But if your aim is to create an image with a sharp subject with everything not in the focal plane a little blurry...isn't that easily accomplished in post-processing?

You 'lasso' your subjects & then blur the background....should be fine for anything up to 8"x10". I'd think they could easily create enough parameters/logorythms that you could make it look almost perfect, and/or creatively different/'better' than the way it occurs naturally.

Am I wrong?