Have you ever seen coal burn? If yes, why?

Yes, I have seen and lit it several times.

I was often in charge of lighting the grill when I lived at home with my parents, we used a hot air gun to light the grill, and it worked really well, we never used lighter fluid, just hot air, and during the process you easily see flames comming up from the burning coal.

Failing that, I used to be an active member of a herritage railroad with steam trains, looking into the firebox of a steam enging you clearly see the coals burning.

Why would you not do that?