I was definitely no fan of Falwell's beliefs, but I would also like to believe that we are more noble, as people, if we forgive.
I think the problem with Falwell was that he became basically a politician who used a questionable and controversial form of religion to achieve nasty political goals. There's nothing religious about being liberal toward the rich and powerful, and conservative toward the weak or the despised.
There is also nothing religious about avoiding reality. If something is not real, it can't be sacred. Falwell encouraged people to avoid reality when it came to gays, and instead did something very unamerican and non-religious. He encouraged them to give into prejudice and bigotry, and made a hell of a lot of money doing it.
I have a hard time remembering a single great religious figure, in any religious tradition, who did that.
The man was a disgrace to the US, and a disgrace to the religious figures he claimed to follow. He used both the US and religion to suit himself, to the extent that he could profit from one or both.
Maybe I am out of step, but if I really love somebody, or a country, or even a religious tradition, the first question I have is not how and whether I can use them to make myself look good, or to make money at their expense. I can't see anything religious or patriotic or even decent in that.
So for me, it's not a question of forgiveness. It's a question of justice, and of undoing some of the damage that guy and his followers did to others, and to the political system in the US. You don't "forgive" a virus that causes an epidemic, or a hurricane after the damage is done. You simply clean up the mess, and try to lessen the risk of it happening again in the future.