I don't think you can pass valid judgement if your method of judging the story is completely different to that which it is intended.
For example, FFXIII is a story intended to unfold over a 40 hour playthrough type adventure, presented in cut scenes, writing and gameplay. There's no way you can judge the whole story by reading a Wikipedia summary - even if you understand it - simply because the presentation of a story wasn't meant for that way.
For me no matter how much you read the story summary and how in-depth it is it's not fair to judge the story without playing the game, albeit sure you can pass judgement if you want, no ones stopping you. Just I wouldn't say you're right to do so.
I guess alot of it depends on how you replace playing the game to find out the story in the first place.
