Morale should be a come back mechanic. It should kick in when your team score is far behind the opposing team as a form of stat boost proportional to the amount of morale you have and drop off when scores become closer. Similar to how Mario Kart gives the last players in the race blue shells and bullet bills to allow them to catch up.
I feel this would reduce the brick wall effect that discourage people from doing pvp and giving them back morale. Tight matches are fun regardless of win or lose. Repeat crushing defeats kills the fun of it.