7 Reasons Open Source Software Should Be Avoided

Reason #1 – Lacks a traceable software development life cycle
Reason #2 – Designed for functionality not robustness
Reason #3 – Accidentally exposing confidential intellectual property
Reason #4 – Lacking automated or manual tests
Reason #5 – Poor documentation or documentation that is lacking completely
Reason # 6 – Real-time support is lacking
Reason #7 – Integration is never as easy as it seems

None of the problem of open source but the issue of any software developed. In closed source, they never get exposed. Classic example of recent ransom-ware bug targeted for old windows XP and Microsoft has to release patch for a declared dead OS. This bug was there for ages but, since, software is closed source, public user can't uncover it.
The beauty of opensource is user can self validate the software and don't depend on software caterer's declaration.