Well the main reason is because it's pointless to supercharge a car, is because it is belt driven. ( I am bias because I love my turbo).

And supercharges can't boost like our turbos can, so it's a bit harder to extract a lot of power for any reasons. Superchargers don't put near the stress of turbos do.
I have seen twin charged DSM's and EVO's out there and let me tell you.
THEY ARE KICK ***!!

 

so much info
ok so you say that the turbo is better for the 4's but what if i have a v6 3rd Gen. Eclipse would the super be better for the six then it would be for the 4?