The perfumed prince pantywaists in the Pentagon have probably determined that the bayonet is too mean and scary to our enemies (oops, is enemy a hateful term?).
This is not the first story of the modern British Army resorting to use of bayonets out in the sandbox.
I know as far back as the Korean War, pundits have routinely recommended the bayonet be "phased out" as an antiquated form of fighting. The Korean war proved those pundits to be pretty stupid.