Personally I think the problem is in relying on just a stack of sats to defend a WP...bad idea IMO. They don't move and really aren't very viable (by themselves) except in early games. You saw how easy one BB knocked 'em off....
In combination with a base or two, now that's another story entirely. I generally pick my strategic WP's carefully (chokepoints, etc.) and defend those with bases, units, ships, etc. - more than just one type of vehicle.
I agree with using 'em and they can be built anywhere, no maintenance, etc. but just don't rely on 'em for primary / only defence. They're just units after all....
