i don't get why it's such a crazy idea that jake is legitimately wesker's b*stard
. i mean yeah it definitely feels like an asspull thing, but it's really not that big of a deal. before the mansion incident, wesker lead a relatively normal life. i mean he was a researcher for umbrella so he was always evil, but he didn't go off the deep end into super villain megalomaniac status until after RE1... and wasn't he in his 30s then? given jake's age he was born before the mansion incident... and i'm not saying that wesker had a wife and was a loving husband or anything, he just knocked someone up - maybe a fling or a girlfriend or a one-night-stand kind of thing. i don't think he even KNEW he had a kid. because if he did, he probably would have done something about him... experimented on or even killed him.
and that's why we never heard about him... because nobody else knew about him until this game. he was a total surprise, outed only by the outbreak and how he couldn't get infected.
at least that's my 2 cents