If mules can't reproduce why are male mules usually gelded?

Entire male mules are notoriously difficult and dangerous to handle, and they can be very determined to gain access to females and may attack other equines during times of frustration or when in close proximity to mares. However, when kept as geldings, male mules are much easier to handle and seem less stressed. Due to their parents' different numbers of chromosomes male mules are considered sterile and as such they have no reproductive potential. For these reasons it is always advisable to castrate male mules, and where practical to do it as young as possible.