If you want to make photorealistic images, go buy a camera.
That's the classic argument I was thinking of.

I think I've forgotten most of what I know about drawing realistically. I used to be better at it. Especially, my life drawing. I went to a figure drawing event a year or so ago and was surprised at how much I sucked at it. I just don't practice it enough to maintain the skills I used to have. That said, my process for producing finished illustrations now kicks the fanny off of anything I could do in college when I was a drawing machine. I wouldn't trade that in.
Hey your green flying piggy is awesome!

Keep up doing what you are doing best ;p. Realistic stock vector has it's place say someone needs a huge print (ex: near a highway) and wants a top quality specific image there, else like you say, buying a camera is the way to go hehe :p