^ Like Jijifli said earlier, this is technically criticism, (and not constructive criticism). If going by your own advice, you shouldn't have said this. So you in your own words were just "impolite,rude,unsettling and not appreciate".
Also, relating to this comment; I criticize myself all the time. Like when I am on my RDM and I forget to use my manafication when I am 40+/40+ and start the melee combo, it just completely ruins the RDM rotation. It's really stupid of me to do it, as I should always check to see that the bars are 80+/80+ , because if not, I have to build up that mana again I just wasted and I lose a lot of dps. (Plus I really enjoy the Verholy's and Verflare's at the end, so I feel angry when I ruin that great feeling of casting it for myself).
As for constructive criticism, it is a very real term in the english language, and when I was doing a paper at university called "Communications in the Sciences" they discussed constructive criticism at length, about what it is and what it isn't. The bare bones of it, is basically criticism in a polite way, combined with advice as to how to improve. As in "This is what you're doing wrong, this is how you fix it". And it is only given if the person thinks it would help the person they are giving the constructive criticism to in the long run.
By your earlier comments, I think you are getting criticism mixed up with Destructive Criticism, and example of destructive criticism is "Your dps is bad, you should uninstall the game." This is criticism that does not help the person it was given to in any way, shape or form.
Also, your comment sounded really patronizing, I don't know if you know it, but I'll assume that you didn't mean it to be. For example, that "Lol" and dismissing what I said as fiction, could give the impression that you could be laughing at me/my comment, and don't think very much of it. And assuming I only use it criticize others and I can't take criticism /don't criticize myself?
That kind of tone is really going to rub people the wrong way, and in the long run could be damaging to your discussion. People are not going to convert to your way of thinking if they think they are being insulted.
^ And this? This comment is almost textbook condescension.
They also discussed in the paper how important neutral tones were in discussions, because accidentally offending someone is not the way you change their minds about something. Neutral tones can help prevent this. Neutral tones also tend to make it easier for people to read and understand a point. So I again, am going to offer my friendly advice to maybe have your tone more neutral, as I think it might help you in the long run. You are welcome to take the advice, or leave it.