This really just the same old, "Well, I'm not used to using it and don't know how to all of its tools, therefore it's not as usable/efficient and thus not as good." That's nonsense.
No, you are wrong. It isn't nonsense, workflow and usability are extremely
important for productivity in a professional environment.
The thing of it is, though, since it's open source, with a little know-how, one can figure it to be as usable and efficient and he needs it to be. There are also several builds out there (like five or six) that have been designed to function more like Photoshop.
I'm sure our IT department would love being required to support all of them.
This seems to get missed by a lot of people for reasons I've never understood. Not all Photoshop users are freelance graphic designers. Some of us are staff artists working in large corporations who have spent years building skills and workflow using certain tools. Some skills are easily portable across software. Some are not. And especially in these environments, having a support line is a necessity. Further, when you're on a deadline... and this applies to anyone doing paid work, not just people in a corporate environment... you don't have time to toss out your old workflow and build new ones.
OSS is great. In principle I love it and have frequently used many OSS projects on my own time. But at work? Frequently OSS just can't compete with the tools that have large development budgets behind them. And to dismiss it as just "people are lazy" as you seem to be doing is entirely missing the point. Even the GIMP project itself is clear that they do not have the same vision as Photoshop
and thus will never do things the same way. And that's fine, more power to them. But that means that for the foreseeable duration, Photoshop is the right tool for a lot of jobs.
Hatred towards Adobe? No one forces anyone to use Adobe products. Why waste emotional energy like hating when all you have to do is ignore them?
I will happily go on record to say that, yes, I absolutely can't stand every single project that Adobe pushes out. I hate Adobe. Hate hate hate.
Except Lightroom. I like Lightroom still. For now.