Wow, I feel really bad for the people that had to go there. Even with the church's policies regarding gays and pre-marital sex, there are certainly better ways to get your point across without driving people to tears.
My high school had us go to a similar event. Although, my theology teacher said something along the lines of "Wow, that was a lot of BS" when we got back(the assembly began during my theology class, but was for the entire school at the same time/obvious), as the speakers said stuff like condoms don't work, cohabitation doubles the divorce rate, etc. Even if what they said was true, the speakers also relied on a lot of logical fallacies in regards to what they said about condoms, divorce, porn, cohabitation, etc. The most logical speakers were some nuns who pretty much said abortion was bad, and that even though it is an embryo, it is still life, etc. Also, like it appears the speakers at this school did, some of those at my school(as well as what my school's administration would sometimes do) talked about how all that matters when voting is ending abortion and making sure gays can't be married.