Who has a problem with the following "Affirmations of Humanism: A Statement of Principles" and why?

It is a matter of choice. In one sense, everything said can be considered scriptural. Any Christian could follow those rules. At they relate to ual freedom, a Christian has that, but a Christians choice would be according to Gods laws As for not looking for salvation outside of nature, God is nature and He is where we get our salvation. If you want to substitute Humanism for Christianity, it can't be done, but many Christians could accept these Affirmations and make them Christian.