I don't know man, Casey had a pretty solid 7 year run with the Reds. From '99 (first full season after the trade) through '05 he averaged 140 games, .310 BA, 17 HR and 82 RBI (and that included an injury plagued/shortened '02 when he batted in the two-sixties). His OPS. ranged from the high .700's to the mid .900's. Again, it's not to discredit Burba or to say that Casey was a great player, but it's more about getting value for an asset. Casey was a 2nd round pick just a few years before the trade, and had advanced through the system quickly while hitting everywhere as an under-aged prospect. At the time, he had a lot of trade value. And if coupled with others, should have brought back a marquee player. (As an aside, it reminds me of the Ubaldo Jimenez trade. I don't judge the trade based on Drew Pomeranz and Alex White not turning into good players. I judge it based on the fact that Pomeranz and White had more value as assets and should have brought back a greater return than Jimenez. Whether or not they developed is irrelevant because the deal was made when they were prospects and at the time they were thought to have a high probability of reaching their potential).
And Richie Sexson, although probably overrated, put up a 30 HR, 100+ RBI season *before* getting traded in 2000. He went on to put up 29+ HR and 100+ RBI in 6 of the next 7 seasons (around an injury in '04), including two 45 HR seasons.
For the sake of this conversation, Giles was traded in '99. That's three straight years so it's not like these guys were so far spread out that they all weren't on the radar at the same time.