Companies respond in different ways to disclosures, by independent researchers and by people under contract. You are absolutely right that in many cases the findings end up in a drawer. This is a real pity. Invariably those will sooner or later be exploited by the bad guys and then the company has a serious problem: they will have to show their homework and if it is found that - at least in Europe - they were aware of the issue but did not take action it may well have the effect of changing a warning into a fine and a fine into a larger one.