The main reason I look at ratios is to try to quickly identify a spammy follow versus somebody generally interested in my tweets (perhaps they're a friend of a

The main reason I look at ratios is to try to quickly identify a spammy follow versus somebody generally interested in my tweets (perhaps they're a friend of a friend, or were searching a keyword I recently tweeted about). If twitter had a better way of preventing spam follows, then I think this would be much less of an issue.