I know I've told this story before, but Big Son was asked to leave his local primary school (in the days before Aspergers was routinely diagnosed) They couldn't cope with him, he was disrupting the other children's education and we did have the energy and resources to homeschool him. So we did, hoping to get him into a secondary school that would suit him better. Unfortunately when the time came he was one of 17 children in the borough for whom no secondary place could be found, and we sent him to a school in a neighbouring borough that had been re-branded, re-opened without the parents and children that had caused the complete break-down of the school and given a "superhead" who was keen to try out alternative educational strategies which seemed a good fit for our son.
All went well until the banished parents and children demanded that they should be allowed back, the local council changed and stopped the special funding that the school had been receiving, and DS1 was mugged twice, one at knife-point for his Pokemon cards of all things.
We were very fortunate that he passed the entrance exam for one of the very well regarded 13+ entry state grammar boarding school. We scrimped, and saved and remortgaged to afford the boarding fees, but it absolutely saved him. He felt safe, they provided an education that was aimed at his level of intelligence rather than making him feel like a freak, and the pastoral care was perfectly tailored for his needs.
He either came home or we visited him at every possible opportunity, and he was a short train-ride from one set of grandparents which meant we spent a lot of time there with him. We did not abandon him, he had all his educational and pastoral needs met and as there was no school locally to us that could do this or had space for him what other option did we have?
Having said that, I would not have sent him at 7 or 8 when we first started to home-ed him, neither he nor I could have coped emotionally.