They don’t do enough for the team overall, yes.
Squishy ATs all either have powerful buffs (defender, corruptor, mastermind), strong CC (controller, dominator), or insane damage (blaster). Armored ATs either have high damage (scrapper, stalker), AoE taunt (tanker, brute, kheldians), or decent damage and buffs (arachnos). This is because being tough is not in and of itself a contribution to the team.