Fractals is a fraction of content though, there are places where having a tanky build is a lot more useful than having a dps build. Of course, you need dps regardless, but there are some tight areas where you can't really avoid damage, and someone needs to take the heat for the rest of the team. The dredge dungeon asura path for example.
As much as I am not a fan of tank & spank, and assuming that you're not running a team of only warriors either.
Much of the fractal content gives you plenty of space to dodge, and relatively few enemies at once. So a skillful player can avoid a lot of that damage with good skill use.
Btw, post your builds for us to learn.