Part of the fascination with Little Warriors stems from the cultural contrast. For a global audience accustomed to sanitized playgrounds and "everyone gets a trophy" mentalities, the sight of a determined six-year-old gritting their teeth through a boxing match is a culture shock.
If you appreciate cinema that sits on the bleeding edge of reality, where the safety rails of "fiction" have been removed, yes. It is horrifying. It is beautiful. It will leave you staring at your wall for thirty minutes after the credits roll.