Word processors are professional tools, but they're also student tools, amateur tools, etc. They (and MS Word in particular) come pre-loaded on computers, given

Word processors are professional tools, but they're also student tools, amateur tools, etc. They (and MS Word in particular) come pre-loaded on computers, given out by schools, etc. You've got a larger population with a larger range of goals trying to use them. And when someone transitions from student to professional, they're likely to continue making do with however they were using Word before. Photoshop is a tool that you have to specifically seek out, whether that means buying it or "acquiring through other means". It's got a smaller population of professionals and hobbyists who are used to thinking of it as a tool. I think that's where the difference comes in.