Not sure but I think this should be accurate.
One of the main things people don't believe people can make a ki ball and have force behind it cause that you have to be psychic to do so.
Really I don't know anyone that can move anything with there mind but here people thats moved matchs or a ping pong ball. I guess if u ever noticed in those dbz shows that some of the stuff looks more esp like cause lifting an object isn't mainly ki/chi etc its more telekinesis. So really if u want to make a ki ball and then have force behind it your going to have try to train doing some kind of esp excersise or something. And thats why people saying they can destroy something with a ki blast is really saying i can lift up that chair using my mind or fairly close to that. Thats my opinion.