Things I can blame on ninja: finally seeing what graphviz / dot files look like, in their textual form. Which is really neat! If you wanna generate a graph from a program, definitely look at graphviz and its various tools like dot.
Things I can blame on programmers: when "ninja -t graph | dot -Tpng -ograph.png" gives me a 50meg file that is over 18,000 x 32,000 pixels. Which is due to the size and complexity of the code base.
On a positive side, my part of the job was mainly getting it to build in a non broken way. Not writing software several times the size of Jurassic Park.