You never cease to amaze me
.
Raiden in MGS 2 was extremely tormented about his past, to the extent that he blocked out his memories instead of facing them
. Solid Snake established himself as a legend by defeating Big Boss in Outer Heaven (twice) and also for successfully stopping Foxhound in the Shadow Moses incident. He never had to rely on the fact that he was Big Boss' "son".
The strain of Foxdie in Snake took years to mutate, up to the timeline of MGS 4 - where it had the potential of becoming a biological weapon on a massive scale. He never knew about it, until Naomi ran his blood test.
Either you're trolling with asinine comments, or you're just incredibly ignorant on basic facts of this series.