Unwanted help is unwanted help. Or are you the one who decides what is unwanted and what is not? Stop meddling. I don't want you to tell me the tactics. Especially not publicly like I don't understand how a game for 12 year olds work and emberass me and hurt my feelings.
The OP didn't say "Pfaphfard let me help you with your DPS you won't be so bad after I show you what to do". He just stated a fact and then asked if that person wanted help. Obviously some see that as an insult and some don't. You also don't always have to be constructive either. There are more ways to motivate someone to actually be part of the group they joined and contribute.
But whatever. If this is the opinion of so many then I won't be doing my best anymore in content where I don't belong (according to some) and where I only come for some quest items (I'm not really enjoying the experience anyway so I rather go afk half the time).