Let me level with you here. There is'nt really a definitve way of watching anime and scoring them on some arbitrary scale. For those not even in the bussiness of critiquing, the very concept of "awarding" anything at all, especially, Japanese cartoons is a purely subjective endeavor. Can't escape the fact that being objective is anything but what MAL users are. And to go further and argue that in a perfect world everyone's average score would be smack dab in the center of this wonderful scale is a silly idea. Why? Because people don't watch bad shows. Or read bad books. Life is too short to go on some holy pilgrimage of watching every single anime or read every single panel of manga ever made. And even if they did, and oh boy belive me I was dumb enough to try, they'd be hardpressed to find legitimately bad anime. Not gonna lie I almost dropped out of college because of that. And besides, no company or creator actually sets out to make bad products. So let's keep it simple and let's keep it to the point. You score anime based on how you would recommend it to a friend. That's what the rating scale actually means to me and probably should to you as well:
10-MASTER PIECE: The epitome of animation. Very rare. Might even say godlike. A true magnum opus straight from the heavens above. If your friend were dying of cancer, you bet your ass you'd set this up for them.
9-GREAT: Amazing storyline with great animation/artwork to boot. If you haven't watched it yet, you'd really be missing out on a lot.
8-VERY GOOD: Held itself quite well and is well above most anime. Probably a must-watch. Most of my favorites lie here. Highly recommended.
7-GOOD: Really Interesting. Fun. On my recommendation list. The anime was everything it claimed to be. And that's a good thing. A world of only Citizen Kane movies wouldnt't be fun at all. We need superhero movies and we need romcoms.
6-FINE: Anime was decent, but had nothing going for it. Good for killing time. From what I've observed, these shows tend to have a lot of interesting ideas, but fail to deliver.
5-AVERAGE: Contributed nothing. Not good, but not bad either. You're better of not watching unless you're fine with the status quo.
4-BAD: Plot was a mess. Had nothing going for it. The anime studio probably either gave up trying halfway through or realized what they had was unsalvagable.
3-VERY BAD: The animation studio probably lost sight of where they were headed. Or was created purely for some deluded belief that it would become a cash grab.
2-HORRIBLE: This is where you realize that just like any other medium, anime too isn't all good. It's actually a pain to sit through this. You'd rather torture yourself than sit through this.
1-APALLING: Must watch. After all, you rarely see anime that is so bad, that you'd actually want to check it.