Excellent question. I thought the same thing when I read it a few years ago. I even wrote a treatment for a script for it (yes, a literate pilot - can you believe it ?) but got nowhere.
Feedback I received from agent and production companies was more related to Apocalypse Now and the feeling of it having 'been done'.
BTW, IMHO Blackhawk Down was boring. Very well, 'realistically' made but no fun to watch and characters not engaging. Didn't care what happened to them. Maybe I've been in Africa too long as none of it makes any difference in the medium term anyway...