...I'd also like to know what You think...Short answer: needlessly punitive.
Your example not only cuts the score in half for John and Maria, it also harms them indirectly by giving Matt 6 points when he would otherwise get None (since he is effectively 3rd). I don't see this as serving any useful purpose, although it may be a curious way to play.
I am sympathetic, though, regarding your misinterpretation. I, too, puzzled at the indefinite narrative language when I first obtained the game and scanned the rules: if several players tie, the points for the respective places are shared. Closer examination of the provided example brought the needed clarification: Kim and Nina each have 4 towers. They share the points for 1st and 2nd place...