The objections are as follows:
that we are at war and this is a distraction
that we shouldn't force these changes on the military when there are still objections and concerns, particularly in the Marines
The reason they both fail -
the bill which will be voted on does not lift the ban on gays serving in the military. It merely authorizes the president and the military commanders to lift the ban at their own discretion and in accordance with their own preferred time line.
The fact that we are at war, in other words, is besides the point since the bill merely gives the president and commanders the option (and not the command) to lift the ban. Should they decide to do so, the president and the Joint Chiefs of Staff can postpone any lift of ban (which they might support) until either or both wars come to an end.