I believe it was meant ironically. Similar to the joke "I double rot13 all my emails, but I'm probably just being paranoid." (If you're not familiar with rot13, running it twice results in the original plaintext.)
It's a joke, but at the same time, I doubt the pattern-recognition bots correct for it, so it would likely have some effect security-wise, to the same extent you get by spelling 'shit' as 'sh|t'.
Honestly GMail is perfect for the threat model of the mails I use it for.
It's very well-defended against random leakage across the Internet, against hacking attacks, etc.
The government has an easier time of getting access to it if I piss them off, but if I do piss them off enough they can essentially invent bad stuff regarding me anyways, and I'm screwed no matter what. Once I came into karmic balance with that I accepted it and went on with my life.
Of course, what's good for me is not necessarily what's good for you.