Human Sexuality

This is a paragraph from UALC's "What we believe" which among many other topics, addresses human sexuality:

We believe that our sexuality is a good gift from God. Sexual intimacy is blessed by Him when expressed according to God’s design, within the context of monogamous heterosexual marriage. Outside of that context, sexual intimacy, whether heterosexual or homosexual, is sin. All who desire to turn from sin, sexual or otherwise, can be forgiven and renewed by the grace of God in Jesus. (Genesis 2:24; Exodus 20:14; 1 Corinthians 6:19-20; Romans 1:26-32)

And yet when 92% of the voting members of UALC chose to leave the ELCA synod because after 22 years of parsing words and cutting corners a tiny minority of members of a task force had decided that God could bless homosexual unions among our clergy, good friends have decided to look elsewhere for a believing congregation. They said, "The percentage voting to leave surprised me and made me feel unwelcome. I had no idea the congregation was this conservative."

Like they had been worshipping and serving on a different planet. I wonder what they thought the phrase "monogamous heterosexual marriage" meant?