As a tank ur interrupting healers, ur stopping people taking a base, ur protecting ur healers, without you, your team would succumb much faster to people who are doing 200k a round. Not to mention if you can distract the enemy healers, their team mates will drop fast.
My friend your just a terrible player who thinks he can run into 5 enemies and survive, as a tank me and one healer can hold off 6 people from taking a base.