Because it does'nt show the distribution of money
whether it is equal or not
EX: 1st person 2nd person 3rd person 4th person per capita
country A :2500 2000 2200 2300 9000
country B :1000 1000 1500 5500 9000
in the above case country A all the people get equal distribution of money,and in country B only one person gets more money
Hence we can say that per capita income doesn't show the distribution of money of the country,whether it is equal or unequal.