I've always hated defining things by a number. I tend to think scoring in general is pretty stupid, and more often than not it just creates drama. I may force myself to do it eventually. If so, it'll be mostly based off of enjoyment and not much else.
I tend to look for shows that are part of the genres that I'm really interested in, which is why there are very few shows on my dropped list. I always want to give a show a chance though, even if they're from genres I don't typically watch.