Since a multitude of pros hailed Jan as even more naturally gifted than Lance, yeah, I guess you could argue that he squandered his talents a bit. But he's only human, and he wanted to party a little.
On the flipside, he had the honor (?) of being held up against what became the gold standard of Tour competitors for almost a decade. Not too fortuitous for Der Kaiser because if in some alternate universe there was no Lance, we would be having a very different conversation today.
Jan on a bad day was still heads and tails above most of the riders in the pro peleton. That crash in the final TT of the 2003 Tour still makes me a little ill to this day.