I don't think it deserves a bad grade at all. The imagery is very creative, and I agree it is passionate. That teacher sounds kinda harsh.. what did she give him anyways? I think you should talk to her and find out what she graded it on and why it was lower than you expected. It deserves an a in my opinion and for his grade level.. now that I think of it an A+.

I like this part the most..

I sing of the VICTORY.
The glistening sweat turned into gold.
The satisfaction of running
Creates inner knowledge that I have done my best