Heterosexual marriages fail at a terrible rate; we need to give same-sex marriages a try.
What is the nature of this kind of proposal? Same-sex marriage is a question of what is morally right, what is in accordance with God's will. To say we should give it a try sounds like we are at a buffet and need to decide between multiple, equally viable options. The need with respect to this matter is to decide correctly what the Word of God teaches, what God's will is.
There is much that needs to be learned about same-sex marriages. Some studies indicate that the rate of suicide is higher among gays and lesbians. Some studies claim same-sex partners are frequently anything but monogamous. Even though two partners may be living together, they often engage in sex with other people as well. The clear fact of the matter here is that there is little if any solid evidence to support a belief that same-sex marriages would be any stronger, more durable than heterosexual marriages.