The downside of having fever/battle high is, that you lose way more points when you die. And you give the team who killed you more points too. It's a doubledged sword.

I would keep the incentive with fever to actually PvP, but I would reduce the general melee buff in frontline, especially the 30% mitigation effect for tanks, and I would half the damage bonus from fever and 2nd better fever atm. You can solo healer with a 8killstreak pretty easy as melee, I don't think that is completely counterable.

With that said though, 5.1 is in a month or two, maybe they already are preparing to change it in something even different who knows..