I address this question to Latter-day Saint men in Chapter 6 of Intentional Courtship. The reasons are actually quite profound.
Many Latter-day Saint mid-singles have lost temple marriages. Many are cynical and jaded and believe that temple marriage is for the optimistic young couple with their whole lives ahead of them. I have heard many mid-singles say they had their Temple marriage and their children with their first spouse, and they are just looking for a little happiness with the second. I have heard others say that Temple marriage did not do for them what they had been promised, and they were ready to find something new even if the temple is not involved.
Cathy and I chose to be married in the temple when I was 50 and she was 38. It was not primarily for the physical beauty and surroundings of temple. That didn't hurt, but it was not the reason. We didn't choose this because of a cultural expectation or a sense of familial obligation. We didn't do it because of tradition.
We chose the temple because we wanted to be together for eternity, and to become king and queen of a realm greater than the stars in the heavens or the sands upon the seashore--all heights and depths. It Is the destiny of every Israelite man and woman to become a king or queen. We wanted all the blessings flowing from the covenants of Abraham, Isaac, and Jacob. We weren't looking for "a little happiness." We were looking for an eternity of endless joy. Does the temple guarantee all that? No. But it places it squarely in front of us for the taking. It gives us the privileges to live up to.
Our temple covenants also provide real power to withstand and overcome the evil designs of corrupt people and the turmoil of this fallen world. As Elder Bednar spoke of at the most recent General Conference, we are promised that, through our covenants, we will be "armed with righteousness and with the power of God in great glory” (1 Nephi 14:14; see also D&C 109:11, 22.)
Is all of that contained within a building? No. It is contained in a covenant with God. But we, as human beings, need sacred space where Earth and Heaven meet. We need a place to meet with God and better understand our relationship to Him. It is true that, "the most High dwelleth not in temples made with hands" (Acts 7:48). He dwells anywhere and everywhere he chooses to. His hands built the whole earth and sanctified it. The power is not in the building. It is in what we do in the building. It is in the promises we make and renew, and the promises we receive. We create sacred spaces to house these activities to impress upon the mind the divinity of these covenants with God, and to give us a foretaste of Celestial Glory.
After all you have been through in a consecrated life, where you have suffered deep disappointments, I think you have the right to aspire to every blessing sought by every 22-year-old returned missionary. It is no less real because you have experienced adversity as pilgrims on the path of glory. Don't give up on your dreams. They can still be realized. Because of your experiences with loss, it will be even more real to you than it was in your twenties.
You are all grown adults, and you can do as you please. As for me and my house, we will serve the Lord. We will be a consecrated and eternal Israelite family. I believe, deep down, this is what we all want. It isn't limited to young people just starting out.
A temple marriage does not guarantee a happy marriage, as some of us know all too well. But it does provide promises from God that can strengthen our marriages in a turbulent fallen world if we seize them. It also provides promises of a glorious eternal destiny together, which can unite us better in the here and now.
You deserve a glimpse of eternity now, and the full realization of your eternal potential, at the appointed time, through the atonement of Jesus Christ. He has offered you the power to become like Him. I pray you take it.