I know a lot of people who were turned off of 4E due to a lot of early bad adventures and play examples.
Well, yes. But I don't know how much of that is about the specific adventure(s).
When people talk about early D&D, one thing that consistently comes up is the modules.
The only consistent thing I've ever heard about people's experiences with adventures is that they maybe tried using one briefly once and stopped. Certainly that was my experience, and similarly none of the people I've met who didn't learn gaming in my group used them. And the original post I was quoting noted the comparatively low sales of adventures (keeping in mind that many people read them or use them as inspiration without really playing them). I don't think that most people playing any edition of D&D use published adventures, and I think that's a good thing.
So again, yes, I believe that the first 4e adventure was probably bad, and that many people had bad experiences with it. I also believe that if it had been the best adventure ever written, people would have had marginally better experiences at best. My belief has always been that using published adventures is anathema to playing a roleplaying game. At best, they can save a little time. At worst, they can ruin a game. Worst is more likely, IME. Which is why I've made the case that there shouldn't be a recommended adventure in or associated with the core books, and that producing and promoting adventures is not a worthwhile goal for WotC.
I didn't have fun, my friends didn't have fun, and it basically killed our interest in D&D. Perhaps if the rules had been friendlier, and the adventure had been better, we'd be playing together to this day.
And that's the thing that concerns me about adventures. I started playing at middle school age with some DM's who were by no means great, but made their own material. Once we tried a module. The experience was really a joke. It seemed absurdly artificial, and not much fun at all except to make fun of.
Now, because we had all already played D&D, we were able to place the blame on the module (which was a Dragonlance adventure that I suspect would be considered reasonably good) rather than on the DM or the game itself. But if it had been a first experience, I'm right with you that it might have been toxic to our group and pushed us out of the hobby. Again, that's why I don't believe in adventures period.
As I've always said, I'll take the raw improv of someone with minimal talent over an adventure written by someone who isn't in the room any day. And I truly mean that, having been on both sides of the screen for it. Raw improv is good, and most people, even beginners, have enough sense to let a DM stand on his own two legs even if he isn't the best.