Curse is an entirely separate corporation from the FTB team, thus you need to create a Curse account for yourself. FTB apparently has "partnered" with Curse, whatever that means. In my view, the words "Feed The Beast" are now essentially meaningless and will someday disappear entirely. There was a time when FTB was "the big thing" but those days are long, long gone. Sorry Slowpoke and FTB team, but that's how this casual player sees things. "FTB" as a phrase or term will disappear, and in the future, modded Minecraft will be "Cursed". LOL I'm only half-joking about that, but the best days of modded Minecraft are most certainly in the past now. It was fun while it lasted, but this Curse crap is rubbish, we got sold down the river when FTB "partnered" with that corporation.
Edit: Nothing personal, I've greatly enjoyed what the FTB folks did for us players. Thank you!! And also... FTB "selling out" to Curse pales in comparison to what Notch did when he sold us all down the river by taking Microsoft's billions of dollars. Its not even close. I might be alone in my opinion, but Notch's backstab should go down in gaming history. I still can't believe he did it. ANYBODY but Microsoft, good grief, it just boggles the mind.