Very backwards, but...
My first character was an Empath, and other than a brief solo career in WoW, my first MMO. I PuG'd her to 50 fairly quickly and was still learning about the game at that point. I found an SG, but it was mostly blasters, and so I spent a lot of time keeping their green and blue bars healthy and using my buffs. But mostly, just keeping their green bars healthy since healing and damage were our sole mitigation. (And hey, it worked!)
Later on as my blaster team faded out of the game, I found other friends... a group that used other buffs and debuffs to mitigate damage. I'd still been dedicatedly playing my Empath and didn't know much about other powersets yet. On an Unyielding ITF with them, I realized I had gone through 3 missions and hadn't healed anyone once (yes, I was still buffing and blasting, not just hanging around
).
And that was my proud Defender moment, when things just... clicked... about buffs and debuffs and damage mitigation.
I only pull out my Empath once and a while now, usually for low level task forces or when everything else has been covered and we want a little extra insurance (like MoSTF). I've found other ways to keep my team safe. And heck, not all of my characters have the blue shield, but I play all of them like defenders
