WHY DQ isn't popular in America

Hello!Nice to meet you.
I'm a Japanese.
Well...I have a question.
Why the Dragonquest (In America it called DragonWarrior) isn't popular in America?
DragonQuest is most popular RPG in Japan (than finalfantasy).
It's wonder for me.
WHY?
Could you tell me your thinking(opinion?)about it?

Sorry,Poor English.

America didn't have a tradition in playing RPGs at that time.

Dragon Quest is a far deeper series than FF, although they are my two favorites.

It's harder, more hardcore than FF. But yeah, a lot of ppl played DQ8 on US. This gen, though, they prefer to just shoot things.