How do you articulate: why open source?

I speak with decision makers (either investors or enterprise) and there is always a suspicious push back for open source: 
-difficult to monetize, 
-must be careful not to share “the secret sauce” of the business, 
-security flaws went undetected for years (android for instance)

Of course I can reply:
- even Tesla open sourced some patents to allow the creation of the market
- security flaws are everywhere, crowdstrike and windows, at least you have more eyes in open source 

But I want to hear how do you articulate it? How do you position open source as superior to closed source?

#opensource #foss