You are mischaracterizing what he said. Biden was fed up with people who kept wanting more and more bans on same sex marriage. He felt that a law against same sex marriage was enough. He stated that people who wanted an amendment were wasting time, while the world was going to hell in a hand basket. At no point did he say gays were sending the world to hell in a hand basket, or that gays were the problem.
Biden was wrong on many points. Not the points you state, but on other points. And he admits he was wrong.
Biden was wrong to vote for the law against same sex marriage. He did that because he thought it would end the issue, and he thought at the time the issue was a waste of time. It is an important issue to many Americans, and should not be ended. Biden was one of the first mainstream politicians to realize that, and really pushed for same sex marriage a few years later.
Biden was also wrong when he thought a law could end the issue of same sex marriage. If you want to take away the right to marry from homosexuals, you would need a constitutional amendment. Even trump's hope of reversing the Supreme Court decision would not do it, because too many states would allow same sex marriage, and constitutionally other states would have to honor those marriages.