A big part of that is that the modern rating system didn't start until 2001 and the first few years were a bit squirrely
You look at the highest-rated HS guys there who didn't pan out and they're 2002 (Olsen), 2003 (Mohetau). Honestly, most of the time when I look at ratings data, info prior to about 2005 isn't worthwhile, maybe even later than that