My parents are teachers. Recently, my mom invited my children to visit her classroom for a couple days. At the end of those days, she could understand why I'm homeschooling my son. She finally "got it". My son was in school for Kind, 1st and 2nd. He had kind, committed teachers who actually cared for and loved him but he was having many behavioral issues. The school considered him a problem to be fixed. However, after leaving school, those same behavioral issued have slowly dissappeared. It turns out school was so stressful for him, he wasn't functioning well. School was the problem to be fixed. At first my husband was very skeptical. He wrote an extensive list of concerns that he wanted me to address in our homeschooling, but he did trust me with making the final decision since I am the one who would be most affected. It also helps that on his side of the family all his nieces and nephews are older and homeschooled so we didn't have to set the precedent. One of his issues is the socialization issue. As it turns out, we have a much more active social life now than when he was in school. He takes classes, he is rested and relaxed in the afternoons and so can handle playdates (previously he just needed to wind down after school so we douldn't do anything else). We plugged into the homeschool community and his friends are from very diverse sources, not just his former classmates. He really is growing socially and emotionally in ways that wasn't happening in school. Maybe your husband doesn't have a vision of what a social life looks like when homeschooled. If he needs something familiar and reassuring, charter homeschool groups often have group social activities and networking opportunities. One local charter school meets once a week for classes while the rest of the time school is at home. Another local on-line school has clubs and dances and other social activities. At another local charter school you register for classes from their extensive catalogue and go to a main campus (kind of like in a community college but for homeschoolers). Some of the charter schools actually give you money for books and extra-curricular classes. These charter schools are technically public schools and they are desperately trying to get the homeschooler's tax dollars.
Actually, over the last school year my husband has gone from skeptical to totally on board. However, I can only guess that if my ds had never gone to school, my dh would never have seen the difference and could easily try to explain some of my son's behaviors as resulting from our homeschooling.