Yeah, it's a sad flaw to the fact that a lot of people buy adventures to read them, and not to run them. The end result is: They sell better if they're a good read. SO... adventure writers write them with this in mind.
Whereas, if they wrote them to be easy to run, we'd have much, much better adventures.
I can't help but think (wish) that there is some happy medium. Personally, I want to RUN adventures, not read them. I can't imagine that an adventure written to be run would HAVE to be bad to read. I mean, I don't quite understand why anyone who wants to just read them wouldn't buy a book. I actually think that if they were done really well TO BE RUN, then the reader-types would probably still enjoy them.