Charts are priceless. They have saved my skin so many times!
The people who understand them think you are smart because you show them.
The people who does not understand also think you are smart, and don't ask questions because they are afraid of being mistaken.
It's a win-win situation!
It reminds me of my first-year lecturer I had a "pleasure" to meet during my studies at the Department Of Economics at my University. 80% of students failed his final exam, though it seemed to be extremely easy (and it really was) - I failed it too. And for the second approach to that exam the old Professor gave exactly the same papers with exactly the same problems to solve. I wrote exactly the same things I wrote the first time but I also added some totally worthless pie charts and other histograms to each and every task...
I got 'A' with a note: "it seems you are not as stupid as I thought you were".