Re: Old addage
"Joe Smoe doesn't have the code in front of them to work out why, MS do, and their motivation is to fix it, not to exploit it - get OpenSSL to do something unpredictable or crash, you have the code and it's more fun to find an exploit."
At best the lack of source code deters skiddies looking for a quick hit. Folks who are skilled in the art of computing really don't need it, and modern disassemblers make life very easy for the folks who can be arsed to use them. It really isn't rocket science folks.
Witholding source code from customers just makes it harder for them to help the vendor.