Yes, we need to build bridges but it is not between the “LGBT community” and rigorous church but between the personal sinner and God. The Church has always been that bridge, with loving care calling the sinner to repentance and obedience to the will of God. What a horrible tragedy it would be if we withheld the truth and made the active homosexual feel welcomed in the pew but thus hardened his heart to remain in his sin and reject God’s welcome to him in heaven.
Furthermore, we can't "agree to disagree" about dogmas like the Immaculate Conception, the Virgin Birth or the Ten Commandments. Those who obstinately deny Catholic teaching are also forbidden from receiving Holy Communion. If they are priests, they are forbidden also from exercising their offices.