It's hard for me to understand most of the objections in this thread. Obviously the Witness teaching is that his strength came from God, on the condition that he didn't cut his hair. That was the one thing he had to do to show his loyalty, and he screwed it up.
I did always feel that the account stuck out from the rest of the Bible, but supposedly the larger purpose of the Samson account was to represent "power", as one of God's cardinal attributes, so it made more sense that only one of God's servants would be given super-strength in the whole Bible.