My answer to that is we have only a small account of what was spoken by Christ and the apostles. Jesus walked with the disciples for three years and do you really think that all of what they talked about is written in the bible? The Spirit of God is a discerner of good and evil. Strong meat is for those who by practice have learned to discern both good from evil.
I think that an argument from silence is not going to deter those who under grace may wish to use particular witness means to promote a Biblical sentiment - for which they and not others take responsibility. Romans 14 is relevant here.