Since the mode already exists and it isn't causing any harm, what on earth would be the point of removing it? In fact I'd say this is one of the most promising developments WoT has seen in years. And whatever concern about the random queue being influenced can be solved by just rotating which tier plays frontline at a given time. Though tier 8 is still definitely the tier that needs it the most, and that's a win-win. We get to play tier 8s and avoid the ravages of normal MM, WG now has a much better sales pitch for premiums.
As of the problem that players are too focused on damage and not helping the team, consider that damage does help the team. If you're forcing the enemy to either take cover, backtrack to a repair zone, or continue fighting in a vulnerable state then you are making your teammates' job easier. And its a great thing that you can play different ways, win or lose, and still have little worry about coming out empty-handed. That's something that the randoms are terrible at.
And as an aside, I'd say its more frustrating being on defense than offense because there aren't that many useful defensive positions and so long as the attackers are pressing W, its almost impossible to stop them from capturing points A-F. Whether they have enough time to kill the final objectives is another story though. So you're put in a situation where a typical result is repeatedly falling back until all six captures are done, and then watching the attacking team trip over their own feet wondering what to do about the final objectives. A good compromise for both sides would be making the terrain a little more defense-friendly, but giving the attackers more time.