The problem is that a win is worth quite a bit and the war items are fairly costly. If you are going to win, you can play it safe and stay bubbled. At that point, you will get the cards you earned and the green money and war dollars ect,, but you also can stop getting war deliveries. When you are doing a COM and war at the same time that can be difficult, best to take advantage of the rules and stay bubbled, concentrate on COM and take the win.
Not how I like to play but I get why teams do it. It is an option so you can't really blame teams for taking advantage, the only way to "fix" it is to change the rules. In hockey you would get delay of game, in boxing you would start losing points...