Board Thread:Naruto Discussions/@comment-24120130-20140607191120/@comment-1872728-20140613083330

Hagoromo 1234 wrote: Hagoromo made the moon on his death bed. He died after it. So even if Kaguya was somehow alive at that time, her sons couldn't have stopped the Infinite Tsukuyomi. Well, it's just my theory, it's not perfect. How about when Hagoromo was on his death bed, Hamura gave him his power since Hagoromo was the Jinchuriki of the Shinju, so he would be stronger. Hamura then died because he gave Hagoromo all of his chakra. Hagoromo then got "revived" and battled Kaguya. He stopped the Infinite Tsukuyomi, and sealed Kaguya within the moon as well, but died due to the amount of chakra used, and this is what really happened to Hagoromo.

This explains why Hamura wasn't mentioned that much, since he died. This also explains why the will of Kaguya appeared after Madara approached the moon, due to Madara's chakra reacting with Kaguya's chakra.