Why don't we write machine code?

Two programs to compute sum of squares of first 100 integers.

C version: 

int main(void)
{
    int i, sum = 0;
    for (i = 1; i <= 100; ++i)
        sum += i*i;
    return 0;
}
MIPS machine code: 
   0010011110111101111111111110000
   1010111111011111100000000010100
   1010111110100100000000000100000
   1010111110100101000000000100100
   1010111111010000100000000011100
   1010111111010011100000000011100
   1000111110101110000000000011100
   1000111110111000000000000001100
   0000000011100111000000000001101
     ....

Index