"Shattered my faith" is a negative way of spinning something I feel is actually a more positive thing. My experiences with JWs broke my trust in religious authority, and in other types of authority, too, but what I got out of it was a good understanding of how people manipulate you and screw you over, and how to see it coming before you get caught up in it. It's actually a great feeling to be able to look at everything and make my own decisions based on whether I think evidence of something is solid or shaky.
Some people see it as... some exJW's who become atheists are just too angry or hurt to accept god.
I see it as... some exJW's don't really allow themselves to question everything. They have set a limit on their questioning which they don't feel comfortable going past.