I rarely, if ever, play with "that guy."
I highlighted the two parts I think are the most relevant. You explained to us in one paragraph (a paragraph that takes me less than 15 seconds to read out loud). My question is, why seethe (sp?) through a piece of instruction you hate and don't want or need, repeated 3 times, then get pissed off, when you could, rather easily, tell him exactly what you just told us after the first time? If he doesn't get the idea and still repeats it more, then by all means, "blow up."
I mean why are you allowing a guy ruin your day like that? A guy who, mind you, is only trying to brighten your day, no matter how misguided?
I, myself, don't care for unsolicited advice either, but just simply smile and say thanks, and move on. If it's repeated, I'd go with the advice already mentioned above and tell him I'll give it a shot next time on the range.
I don't ever give people advice while playing because 1) I don't really pay attention to strangers swings, and 2) I don't feel qualified. Occasionally, though, if the right opportunity presents itself, I may slip a little. Thursday, for example. Guy I got paired up with was a 25-ish capper type guy who, after hitting a couple of bad shots, started voicing his frustrations out loud. He complained about not understanding why he was alternately hitting it fat then thin then fat, etc, etc. Well, based on that I knew there was a good chance that his biggest problem was not having his weight forward at impact. Since he "asked" I decided it was OK for me to answer, but I still phrased it something like "I used to have a similar problem with fat and thin shots, and for me, it turned out that I didn't have my weight forward enough at impact. The club was bottoming out behind the ball, so if I hit the ground it was a fat shot, and if I missed, I thinned it. I'm not really certain if your issue is the same, but that could definitely be a possibility." And that was the end of it. (Not really advice, just my opinion of what may be one cause of his problem. If he was interested in trying to solve it sometime, great. If not, that's great too.)
You're right, I'm part of the problem. But I think my sheer hatred for unsolicited advice from a stranger and my greater hatred for advice coming from a 25+ capper get in the way. The way I look at it is, I shouldn't have to tell you (by you, I mean the 25+ capper) I've dislocated my left shoulder way more than 10 times (I lost track after 10) and I've created a swing that works with my messed up shoulder and you're just seeing me on an off day. You shouldn't be giving unsolicited advice or any advice for that matter!