Not trying to speak against what you said. Just wanting to comment on some interesting analogy that you used.
Even if locking my front door is not fully secure, at least it turns the attackers to my neighbor’s unlocked door. Even if close-source can still be abused, at least it turns the attackers (or at least lazy attackers) to easier targets.
Of course they can sue those who violate their license. But they did mention that they don’t have the time for those things. Developing awesome software for us is already something. So just go for the convenient path.
And I fully agree with you. How many will actually go through open-sourced code? Also, false sense of security. Just because it is open-sourced, we think that it is secure.