Correct decision?

Had a really terrible game as Ashe, got stomped all lane and focused in every teamfight. There was not a single point where I was capable of using Flurry in any teamfight, I was dead so quickly. (couldn't kite, even with Swifties. Enemy Nami was doing a really good job of speeding up their Shen to get to me) Given that, I picked up a Frozen Mallet second item after IE (and zeal, so second and a half), in an attempt to keep them from getting to me or my backline teammates, and to survive long enough to output what damage I had. My whole team flamed me and called me bad for not building straight damage and trying for late game.

Is the ADC's only job to do damage, and always build glass cannon no matter what the situation is? Even as Ashe, THE utility ADC?