Umm.. I guess it depends on what you mean by "seriously".
A "bad person" would take things "too seriously" because he would be letting his passions get the best of him, and would be overreacting. On the other hand, a good person can take even little things seriously, if by that we mean that the good person recognizes that even little things can be important and even vital. "Bad people" will often take the most serious of things (life, God, etc.) lightly, while the good man will take them seriously. Yet when things go seriously wrong, the good man is usually better able to handle the situation and not overreact, while the bad person usually loses control and flips out.
I guess I would agree with the statement, but only because the "bad people" are controlled by their passions and the good men are not (or, at least, they are able to better control their passions by the grace of God). So whether little or serious, the bad man misunderstands how he ought to respond, while the good one understands.
I guess I would agree with the person who you quoted, though I imagine we would come to the same conclusion through a very different thought process. Also, I guess I would agree with your last statement, it's a good general observation to go by, but has some very important exceptions.