1) Software is good enough. Apparently. Even if isn't.
2) Upper management can't "earn" humongous bonuses if they spend money on frivolous things like security.
3) The resident Libertarian IT geeks in charge say everything is okay. All they need to do is hand-tweak their current favorite security solution. They roll their own, man.
4) [Entrenched Security Vendor X] told them a patch is on the way. Everything will be okay. Drinks on them!