Well, of course they are.
Where else should be?
I mean, who could predict that there might be rioting and looting in Ferguson and the National Guard might need to be in Ferguson or have a rapid deployment plan to enter Ferguson at a moments notice on the night they announce the Grand Jury will no bill Officer Wilson after weeks of threats by “protesters” that all hell will break out and Ferguson will burn if Wilson is not charged with murder and arrested?/s
Yes, pure absurdity...
Well, can’t say that I blame the NG for not falling out. Keep in mind that they probably have not been and will not be issued live ammo. And, unless Marshall Law is declared which is doubtfull, they have no search, seizure or arrest authority. So, all they can do is show a presence and look pretty - and the rioters know it.