I feel like this discussion wasn't much of an issue until recently... And I can tell you for sure there were plenty of "re-touched" screenshots before now. A screenshot is a screenshot, what a user wants to do with it is what they want to do with it. I feel that unless they specifically mess with the image itself in a 3rd party program, such as covering things, adding images, or renders, etc. that actually change the content within the shot, it's fair game. Honestly, even if things like SHARPENING (Come on, that's honestly something anyone can do, there are free websites online specifically for it...) and in my case, I ALWAYS sharpen my images (some may look better than others sharpened) but it's because I don't have the best hardware, and I use the sharpening to give the image clarity. Should we start excluding people with better hardware because they get better looking shots with better content/higher draw distance/etc.
Also, regarding the original image poster, it looks, slightly edited. "Re-touched" if you will. Nothing looks added to the shot, the water looks like an asset in-game, not something added in photoshop...
A screenshot is a screenshot, I don't think the word is intended to mean anything other than that. Editing doesn't make a screenshot something else. And editing DOESN'T give anyone an unfair advantage, I've seen heavily edited shots get no attention, and non-edited shots get a lot of attention (Not directed at anyone in particular).
To sum it up, I think edited images are fine with color editing, sharpening (again, this is almost necessary in some cases), contrast, etc. But if anything is actually tampered with regarding the content of the photo, I don't think that's a fair thing to allow.
Of course, this is my opinion, as is the other posts. I mean no offence to anyone. (Though I do feel it's a bit silly)
Then again, how do you propose to enforce these rules? How do you KNOW when a photo has been edited? If I take a photo, and sharpen it, are people going to know immediately? Same with color editing? I'm curious how this could even be enforced outside obvious edits.
Again, no offence meant to anyone, just my 2 cents in the conversation.
Edit: caught Epoche3bis4's post above, and agree as well.