Catching Bluffers

I found this little quote in Sklansky's book "Poker Gaming and Life" and is a little confuse in what it means so I hope someone can give me some help on this. "There is a natural tendency to call the aggressive player and fold aganist the tight player when each bets on the end, but both strategy might be wrong. If the aggressive player will bet just as many "bust-outs" as the tight player, his ratio of bluffs to legitimate hands is actually lower than the ratio for the tight player. Thus with a mediocre hand that is only good as a 'bluff catcher', you would be more apt to call the tight player then the aggressive one." I find this quote kind of confusing so hope some of you can help me out thanks