Only a fool would turn down a blind date IMO. There is always a CHANCE that they could turn out OK...and unless you have the opposite sex beating down your door in first place...you ought not pass up that chance.
Just make sure you always go with a "wtf" attitude so you aren't too disappointed when the other person turns out to by psychotic/heavy/dumb/rude/gassy/etc. Also, VERY IMPORTANT, try to always go on blind dates while you are with another couple...so you have someone to talk to if things go badly.
I went on a blind date a few years ago and this gal didn't say $hit to me all night, but my buddy and his girl were there so I had no problem ignoring her as well talking to them. Worst date of my life, but no biggie, I met my wife the very next night!