Nipples are the thickens ends of mammary glands, located at , equidistantly on both sides of the frontal thoracic (chest ) region.
The males have breasts because during embryonic Development the is NO DIFFERENT between the male and female embryo in the thoracic region development.
At PUBERTY, this breast stock of females , as they secret hormones , Differentiated into MAMMARY GLANDS which enlarges to form female breasts as distinct from the Male's.
That's because both embryos of both sexes develop from the same template whose default sex is female. The human breasts fully develop in females only in puberty owing to female hormones.
How about because they were created that way hahahhahah.