the point of an RPG is to play a role in the world. you create and define the character you wish to become. his stats, his skills, his history and most importantly his decisions in teh world. that was the origin of PnP RPGs. this point is completely missed by Jrpgs, hence they are not ROLE-PLAYING games. you are spoon fed everything and just lead your hopeless mess across the story line, its an interactive graphic novel. if you do not have the will, or imagination to shape your own character (with decisions and skills) in a game, then by all means, stick to cookie cutter jap games. but do not for a second think you are a RPG fan.
early RPGs (western) did not have a high reliance on story due to technological limitations (but nevertheless there were rogue like games and zork). however western PC rpgs ALWAYS looked better than whatever the japs were churning out at the time (simply due to the favored platform: PC-western, Consoles-jap)
i am not debating the popularity of jrpgs, hell i have every rpg out on the ps1 & gba (and almost every on psp). and there are tons of great games there. but rpgs, they are not.