If not 'needing another reason' is the criteria for being 'the right reason', then by your definition, we too have 'the right reason'. Principled defense of free association rights needs no additional reasons to be legitimate. It stands on its own.
To bad the libertarians do not support moral values.
Prohibition of initiation of force or fraud is a moral value. It is always immoral to initiate force or fraud. This is an absolute moral value.
Say what you like about us, but it cannot be said that we hold no moral values. Our entire philosophy is based upon one.