Earlier quoted context omitted.
I used Photoshop for 8 years, including for web development, before switching to Gimp. Gimp is good enough for everything one needs in web dev, is free, and has a vital feature Photoshop lacks: the ability to run on a Linux workstation. When developing software intended for Linux servers the value of having a Linux workstation to easily do local development cannot be understated.
Photoshop runs fine on Linux. I pay for it and use it in Wine. Gimp is hot trash and to add insult to injury it's responsible for birthing Gtk; it's a fool me once fool me twice thing. What is this mutually shared meme-delusion that Gimp is anywhere close to an adequate facsimile of Photoshop?
The hyperbolic invective hurled at GIMP by Photoshop users is astounding. I often spend all day in Photoshop and Illustrator doing preprint and it makes me want to burn Adobe to the ground every day. I would gladly never look at PS again if GIMP got color right.