Color and clarity are only 3 points on the BJCP exam, and for good reason. There are bad things which can cause clarity problems, but not all clarity problems are from bad things. Aroma and taste ultimately trump the day. However, I, too, am disappointed when I cannot get my beers crystal clear. But what is the metric? Almost all commercial beers are filtered, they use post kettle finings (Sierra Nevada uses Polyclar Plus, for example), and frankly, I haven't found that customers are all that concerned about clarity if the product tastes good. Having said that, if you don't filter, you need to run down your checklist, beginning with grain, crush, Ca++ levels, hot break, cold break, kettle finings, yeast strain, yeast health, need I go on? At the end of the day, it is Tincture of Time!
Cheers!
NanoMan