Bit off topic (mods, move somewhere better if you like, I guess) but to follow up the causes and pilot error issue.
The NTSB releases various statistical data.
Annual Review of Aircraft Accidents 2003 was the first I checked.
On pages 13 and 14 it has a couple of graphs showing various causes, and also a discussion in the text.
Within each accident occurrence, any information that helps explain why that event happened is designated as either a “cause” or “factor.” In addition are findings that provide information of interest to the investigation. For most of the 10-year period [1994-2003], personnel were cited as a cause or factor in 70 to 80% of all Part 121 accidents, followed by environment-related causes, and then by aircraft-related causes.
Certainly not 99% in that sample.
(Incidentally, "personnel" isn't just pilots; any human error would be counted)