This is a debate that has been going on for years. So many people have tried to find ways to encourage commenting, but in the end it's down to each individual as to whether they choose to or not. Then those who comment also have to find your post. It can take time to build up a following of people who have similar interests to start these conversations. Then there is the other side of the equation where people write a post and never respond to the comments or debate they receive, which puts people off trying to comment.
You can only do what you think is the right approach, see who responds and try to encourage whey you like. You can't force others to do what they aren't inclined to do.