What? Whoever wrote that is discounting what God says about sin, all sin. Homosexuality is an "abomination" according to God Himself.
On the other hand, homosexuality as an act or a pattern of conduct is a sin... in fact, an abomination. Just as is any act of injustice:
Deuteronomy 25:16
For everyone who does these things, everyone who acts unjustly is an abomination to the Lord your God.
Proverbs 6:16-19
There are six things which the Lord hates,
Yes, seven which are an abomination to Him:
Haughty eyes,
a lying tongue,
And hands that shed innocent blood,
A heart that devises wicked plans,
Feet that run rapidly to evil,
A false witness who utters lies,
And one who spreads strife among brothers.
I think we don't realize how desperately wicked these things really are. Those last two, for example, are --- I say this sorrowfully -- fairly common among people, even here at FR, who don't think of themselves as abominations.