There's nothing wrong with a DM not wanting to allow content he isn't familiar with.
If you really want to be able to use the book, perhaps you could lend your copy to your DM so he can at least read through it. Alternatively, if you can afford it, you could buy him his own copy. (Better yet, get your fellow players to chip in.)
It could also be that the DM has limited time and doesn't feel like having to spend it on reading yet another D&D book, even a complimentary copy.