Answer: while controlled fires can be good, there are some bad stuff about them that may happen.
1) the fire could get out of control
2) people that are near, or by the area, have to smell the smoke, which is bad for u lungs
3) people could get burned if they get too close tot he fire
and 4) the animals might not escape quick enough, or have to stay with there young, have no place to go. causing them to die
hope this helped :)