Spike Lee's philosophy on creating these documentaries about Michael Jackson is very specific:
As he stated, a lot of people need to be reminded about Michael Jackson's art, and especially the young generations who might only know Michael Jackson because of negative stuff about him (such as, the child sexual abuse allegations against him).
That is why in his documentaries he includes people who talk and praise Michael Jackson, and technically this is also very easy for him to do it because many people are eager to talk about Michael Jackson and how much they were positively affected by him.