One of the biggest issues I think, is a lack of understanding the balancing act of self-improvement versus "being yourself". As an example, you'll have an individual who may be unkempt, and they'll bitch and moan about not being able to find a date. At the very suggestion that they consider improving their grooming habits to enhance their public image, the individual will take offense and then utter something along the lines of "if they aren't going to accept me as I am then I don't want to date them anyway" and it's pretty much a self-defeating stance to take.
The use of "being yourself" as an excuse to look like a dirty sack of potatoes in public, act like a creeper, or otherwise justify being a lazy bum is a good way to stay single for a long time.