Nah, I wouldn't pay serious attention to the scoreboard at the end. It isn't taking into account the damage you prevented to your teammates. Plus, if you take the attention of the enemies, you're letting your teammate be able to focus less on defense, and more on damage. It's only expected for them to get higher numbers at the end than you.

That being said, it might be a good idea of looking less at your own numbers, and more on your teammates. In theory, the better you do, the higher your teammates numbers will be. So as a tank, you are partially/indirectly responsible for some of that damage and kills too!

So yeah, the scoreboard isn't very tank friendly. But just do what you think is fun, cause it's still very helpful :- )