I agree with
@MrTokay on this one. Newer players that do not know how to play the games well are everywhere, not just in Tower Defense. We just have to be patient with them and try to help them learn. Remember, we used to be the new guys to the games as well. Eventually they will learn. Just try to have fun and not be so focused on winning. As I said before a tutorial may help, but I do not agree with all the suggestions.
For this one, I feel it would take away the fun in the game and the strategizing if the towers were to correct their placement automatically. Sorry but I do not think this is the best idea.