Not to disagree with the general opinion here, but I certainly think uttering words in Abyssal could be perceived as evil, and certainly offensive. Good creatures would avoid uttering words in the language unless absolutely necessary.
That said, it doesn't mean a good creature doens't understand abyssal.
A very close paralell is the langauge of Morder in Middle Earth. Gandalf refuses to say words in the language several times, but he understands the langauge well as a scholar.
I would mainly make it a roleplaying issue, not something with game effects. I certainly think a Paladin would have issues with speaking anything in Abyssal.