Just for that purpose, you're probably right. But if you have people in space anyway, and war breaks out, you'll use them to whatever capacity is possible.
And a totalitarian government like China could very well set up an orbital or lunar colony just to prove they can. In that case, they'llhave so many assets in space that, even if it is inefficient, they'll still win.
War WILL move into space. Just watch.
China has 30% unemployment and can barely feed its people. All those manned space assets are costly in economic terms. Trying to keep up with our manned space program is one of the major factors that broke the Soviet Union.