Havent run any published adventures outside of those I and my group have playtested in a very long time. As for why.. well I'll try and explain my view of them.
Published adventures in the past have almost always taken the following form.
1. you are all in this location because...<enter explanation>
2. while there some need of adventurers arises or someone approaches your group and asks you to help.
3. Group moves from encounter to encounter picking up (hopefully) info along the way that leads towards some locale and plot.
4. Group moves to locale and goes from room to room to room fighting the nasties and looting... occasionally getting a little hint more at the plot.
5. Group finally has enough of plot to get the gist of what is occuring and has a showdown with the main villain in order to put things right.
6. Providing group survives returns to town, gets rewarxd,heals up, etc..
The above 6 steps are without fail the essential rout 95% of published adventures take if not more... its just too linear and its not overly exciting anymore. Encounters are almost ALWAYS combat oriented, little if any effort is put in to include the skills of any other class beyond the occasional open lock and disarm traps..
Myself and my group just like something a bit more open ended, involved, plot oriented and not written in stone.
for a great many years many adventures in my campaigns have taken the form of a basic plot idea, expanded upon with a few encounters i'd like to include of varying types, the major NPC statted for quick use, the odd map scribbled down and any obvious handouts provided ahead of schedule. The rest of it is ad libbed and developed as the adventure progresses and that works heaps better than a published adventure for us.
I probably would buy published adventures if they took the form as say an Adventure toolkit, which could include.
Basic Story theme, nothing written in stone just something to set the scene.
Regional map and maps and info on important locations (towns, inn, shops, caves etc.. provided without specific encounters being put forward).
Few handouts (old map fragment, blank journal entry that can be photocopied and filled in etc..)
A Bunch of Story Hooks suggesting on adventures that could be done based off the Basic Story Theme.
Odd new monster, magic item or prestige to include that is "themed".
And thats it, with the above id have enough useful material to make use of and enough freedom to build upon the story premise to suit.