I think I might have to agree with Umbran on this one, in that I have met several GMs that will "very humbly" tell you that they never use published adventures because the published writers just aren't as good as they are.
I have to disagree with this. Quite a while ago, half a dozen DMs/GMs (none of which used modules/adventures) had a similar conversation. We thought some of the modules were fantastic and we would happily steal ideas from them. But as one guy put it, it was like being forced to play a pre-generated character. There was no soul.
Which, of course, brings us to the rest of your post, which I wholeheartedly agree with. When I 'house' DM, I know what the world is like, what is going to happen/may happen, etc. If I have a guy who wants to be a dragon-slayer, voila, there just happens to be more dragons in the game. Likewise, I get to control many of the aspects (such as treasure) that I find harder to do with modules. Finally, my storylines tend to be heavily interleaved; that is, something in the first adventure may impact the 3rd, 7th and 15th.
And, of course, there's always been the problem of the player who buys all the adventures so he knows what is supposed to happen.
Oh, and I post here because I'm looking for things my perception might not see. Especially since I have a hard time remembering if a rule/concept was 1e, 2e, 3.x or some house rule I created or heard about. So what is the rule now? What do others think about it?