Considering the software methodology of both the open source movement, and the closed source movement, it comes to no surprise that the instinctual reactions of each were made such that they supported each's view on software.
The closed source view was to promote their economic principle of scarcity. They did not openly admit to this major oversight; the backdoor was discovered years later; and they did not react in a speedily manner. Doing so, would admit to users that the bug was indeed an issue to be addressed, and trust in that company's software would diminish.