I wasn't talking about Mary necessarily, though. and the reason why is that i simply didn't know why her quest depended on other quest to proceed since i couldn't proceed at her quest. of course i won't have an opinion about something i haven't experienced
but, for my argument's sake, let's suppose that the person above who said "you have to do a quest of Character X because that same character corrupts Mary, therefore allowing you to proceed Mary's quest" is right and that's the case
an alternative proposal to interdependency, then, would be having Character's X quest and Mary's quest be one and the same quest, with the MC progressing with both characters at the same time in a perhaps dynamic way. Yes, Mary would be an obstacle for those who only do the quest for Character X and vice-versa, but so is the case to people who only care about Marya at this actual moment
also, being honest, i never said that interdependency is inhenrently bad, i don't think it is. i just think that a writer and a programmer can be creative while making a game in a lot of ways, not necessarily being limitedto interdependency and that's all