If it is done correctly. In the state we live in, it is a big thing. They have groups who home school and these groups get together for events and field trips.
I think when some JW's do it, it is solely done to keep the kid out of the "world." If the child is in a dangerous area or is miserable, it can be a good alternative. Some JW children who are so protected can go batshit crazy, once they are let out of the "JW cage." We have seen this happen. Parents have to remain VERY involved.
Home schooling was not a alternative for us. Our kids have turned out fine and have learned how to deal with everyday life and different personality types. Kids have to learn to function.