Fh. Y how fa,ebook, Twitter youtube and ilk can deny people the right to use their social networks, which is open to,the public just like other businesses, for any reason, under the excuse that it “violates their beleifs”, but conservative businesses can’t deny service to anyone based on a violation of their beliefs.
Because freedom to express ideology is not a protected right in the private sphere (thus FR can zot libs) vs, amoral aspects as race, and SCOTUS has wrongly chosen to equate homosexuality as race or ethnicity. Thus since a private entity cannot actually discriminate against people on the basis of race, then neither can it refuse services, even special works of art if such are offered, based on being part of a sexual orientation "ethnicity." This is the tragic immoral consequence of of SCOTUS going to war against God.
However, since the likes of FB can censor those who express ideology that is associated with a non-PC color or race (like removing Dr. Seuss books) under the broad category of Terms of Use as "hateful," "offensive," etc.) then since homosexual marriage is an expression of ideology then one could try to justify refusal on that ground.
Be wise now therefore, O ye kings: be instructed, ye judges of the earth. Serve the Lord with fear, and rejoice with trembling. Kiss the Son, lest he be angry, and ye perish from the way, when his wrath is kindled but a little. Blessed are all they that put their trust in him. (Psalms 2:10-12)