Yes, I was able to google the article "Should homosexuals remain in the Catholic church?" by Gregory Baum.
Baum is a liberal Roman Catholic theologian. The quote reported above is not Baum's opinion, but Baum's summation of Roman Catholic teaching. From my reading I would say that Baum is being accurate and is not exagerrating.
Baum, nevertheless, concludes that LGBT Catholics should remain in the Catholic church and dissent from the church's teaching as their consciences demand.
I'm sure one could argue to other conclusions than Baum's. From a Soulforce perspective one would not want to cooperate with the "evil" of the church's teaching--maybe that would be an argument to leave the church. One can also stay and make one's dissent known. Whatever one does, one needs to consider one's own spiritual well-being.
I feel I face much the same thing as a dissenter within the United Methodist Church. We now have a church ruling that allows pastors to deny membership or threaten church discipline to LGBT people who refuse to "repent" of the "sin of homosexuality." The situation is hardly any better than the Roman Catholic one.