You're probably right about people in general not having a clue as to the right approach without reading the spoilers. I am an avid puzzle and riddle aficionado. One kind of puzzle I see is identifying someone's ATM PIN using a constrained version of this. I incorrectly assumed people who enjoyed my challenges to have the same kind of exposure and recognize it as being similar :-(
Personally, I enjoyed the challenge of trying to figure out what the message was as well as coming up with a general solution (which has now been fixed). I worked out that C,S,0,1,M,E were statistically significant, but I couldn't make heads or tails of what that could possibly mean so I did eventually have to look at the spoilers to work it out.
I just wish I had more time to spend on things like this instead of doing actual work :)