I would gently suggest that Photoshop Elements or Pixelmator are probably more likely to be of value to such people. Pixelmator is something like $20 and vastly more user-friendly than Gimp.
When you can get something that good for $60 there is absolutely no reason whatsoever as to why you'd put up with something like The GIMP. None. Photoshop had things like Adjustments Layers since 1996 with Photoshop 4.0, the same version that introduced an easy method to make your own automation (macro recording). 1996. The GIMP can't beat something that was made in 1996. I'd rather put up with a VERY old version of photoshop running under a PC emulator with an old OS than use the GIMP. That's how different the two software package are, and how useless The GIMP is.