As a Christian, I believe in Christ's words:
"If any one of you is without sin, let him be the first to throw a stone." (John 8:7)
So while I do not agree with everything Mr. Falwell taught, I have no right to lamblast him in a public forum, either.
He did do good things--he is often credited with getting born-again Christians involved in politics; before his time, evangelicals were taught that the church should stay out of the state's affairs. They now make up (depending on whom you listen to) somewhere between 25-33% of voters. Liberty University, which he founded, has produced solid Christian people and leaders; for those of you familiar with the band d.c. Talk, that's where they met.
In short, while he wasn't perfect, none of us is, and as such, I want to make sure positives are brought out.