This issue is unimportant only if people’s salvation is unimportant.
Some passages (e.g. 1 Corinthians 6:10) say that practising homosexuals will not enter the Kingdom of God. Almost all link homosexual practice with judgement. Many passages link sexual immorality with not entering the Kingdom of God. If the Bible is correct about that, then this is a major issue affecting the eternal salvation of practising homosexuals (and sinful heterosexuals). Any Christian with genuine compassion will be motivated to take this seriously and to warn homosexuals.
The whole of the biblical story is about sin and its consequences and God’s giving of His Son, the Lord Jesus, to die paying the price for our sin thus making it possible for us to be forgiven and reconciled to God. This is the theme of the Bible from Genesis 3 when Adam and Eve first chose to disobey, thereby damaging the “very good” creation that had existed previously. It runs through to Revelation 22 where we see God’s Kingdom and its original perfection restored.
Homosexuality is only one aspect of mankind’s disobedience but it is still one aspect of this big issue in the Bible and we are told that those who choose to engage in it will not enter that Kingdom.
Christians should not focus on this issue to the exclusion of others but to say nothing would be the most unloving thing a Christian could do to a practising homosexual. It would indicate lack of concern for his/her eternal salvation, or maybe greater concern for ourselves than for others i.e. we avoid the unpopularity but at the expense of others going to hell.