Reflection on a mystery writer

First I read The Judas Window by Carter Dickson, bought for the minimal investment of a dollar at Commonwealth Books in downtown Boston.  I hadn't read a mystery in a long time (with a very few exceptions, such as Dissolution by C. J. Sansom), but this locked-room mystery was a novelty that sparked my curiosity.  As I read, the courtroom drama engaged me; the barrister/detective, Sir Henry Merrivale, was a droll character.  A few months later, I moved on to The Scandal at High Chimneys, written under the author's actual name, John Dickson Carr.  This was an altogether different sort of mystery.  For one thing, it was set in (a carefully researched) Victorian London.  Overall, it was no less entertaining than The Judas Window...had I found a new direction in the area of light reading?

Simultaneously, I had noticed that I could find books by John Dickson Carr (or Carter Dickson) only in used bookstores, sometimes.  I wondered, why had this excellent mystery writer fallen into obscurity?  Then I bought The Hollow Man.  It was a puzzle.  By that I mean The Hollow Man focuses almost exclusively on murder as puzzle.  The characters--although they often feature eccentricity, minor or major--manage to be dull.  Similarly, the detective, Dr. Gideon Fell, is eccentric but ultimately dull.  Meanwhile, though it becomes clear that the victim had a criminal past, the link between the victim's past and his murder--which soon becomes two murders--is as clear as mud.  Thus, neither characterization nor possible motives compelled me, and I felt dragged along to the wondrous puzzle of it all.

I did not feel wonder.  I felt something between annoyance and boredom, especially during chapter 17, "The Locked-Room Lecture," which I skimmed, then skipped...have I been spoiled by the complexities of, say, a P. D. James mystery novel?  Or, had I discovered why John Dickson Carr has fallen into obscurity?  In any case, I am now reading Sovereign by C. J. Sansom (and dedicated to P. D. James!).