It should not, IMO.

I heard this so many times before in the past 25 years, still it misses the core points:

• Public source code enables others to perform (security) analysis of it, completely independent (or even unknown to) the original code authors, with methods of choice.
  That fact poses a significant threat for "special, undocumented functionality" to be detected someday (if it exists in that code), likely having an enormous impact on any business utilising that code (i.e. that is the "threat" for the company developing that software).
• Source code under FLOSS licenses allow for others to enhance that code, even if the original authors lost interest in it.
• Properly hosted public source code allows for retracting who committed which parts of the code when at any time. This transparency eases many technical and social aspects of software development.
• Properly hosted public source code is accompanied by a public bug tracker, at least publicly documenting known bugs, but usually also enabling everyone (including you and me) to file observed bugs.
  One does not need to be a coder to contribute to FLOSS!

All this (and some other more minor effects) usually lead to an environment, which I structurally trust much more than any hidden and closed software development model, even without personally knowing anybody involved in it.

P.S.: Wow, Windischeschenbach really exists. I suppose one could hardly pick a better exemplary hill-billy village in Bavaria with such a sounding name.