Shoot, you guys are much better brewers than me. I honestly don't remember my early years all that well (1998-2003) but I definitely had more bad batches than you guys are talking about, not to mention the average/poor quality of the beer, at least in first year. I'd guess I had 5-10 bad batches/infections in my first 50 batches. Once I started using StarSan that really dropped off.
Since I picked things up again in 2007 I've had a couple of bad batches, maybe 2 out of 30? Although only a few were really BAD, I've still dumped quite a bit of beer. I'm pretty picky about the beer I drink. Even now that my brewing and process has come so far, I still dump probably 15-20% of the beer I brew. If the beer I make isn't up to the quality of beer that I would buy, I usually dump it.
I just dumped 20 gallons a few weeks ago, a dry stout which was a little too astringent and a Rauchbier that had some fermentation off flavors from a higher temp ferment. I have 10 gallons of mild that I'm considering dumping. It's a pretty clean beer, but it's just not as malty as I wanted. I just don't have any qualms about dumping beer I don't like drinking.