It's the sense of entitlement that Andy should never make mistakes for their sake, not his own, that winds me up.
I'm sure we're all guilty of shouting "over the net" or "inside the lines please Andy" and other highly insightful advice at the tv, but it's a bit presumptive to think everyone else needs to read it. No-one thinks a double-fault is good, so while it's reasonable to think it's bad, who does it help to labour this point?
I think you're just describing the online conversations
between fans experiencing and discussing tense moments in a match. Of course, we are maybe stating the obvious, but whether it's a great point won or a point lost, it results in comments on the thread - "Discuss the match"
Frustration and jubilations are vented at the highs and lows of his matches, but what's wrong with that? I cant see any evidence that Andy's fans think he's winning or losing matchs or points for their sake. What I do dislike is members posting vulgar expletives, directed at Andy (and/or others) that's uncalled for and horrible to read.
Personally I like to read other peoples comments (though I may not agree with some) since I watch all tennis matches alone.