This is just old "conventional wisdom" that is neither anymore. BYO has a recent article that confirms that secondary is unnecessary for most ales. In this article it was also mentioned that leaving your ale on the yeast for up to 6 weeks does no harm.
I used to use glass only and and rack to secondary all the time. I got tired of the cleaning and weight of hauling around fragile glass. I now use buckets for most of my beers, and they are as good as ever. Also, if you are not planning to re-pitch your yeast, you can dry hop in primary after the beer has stopped dropping gravity points. I listen to the Jamil show often, they almost always do a single stage fermentation.