Er, no - 60,000. You're off by a factor of 100 (or two orders of magnitude, depending on how you want to look at it).
The author claims A320 in 1988 (a quarter century ago) had 60,000 lines of code. And
since then the size has increased by two orders of magnitude. So a comparable a/c today has 6 million lines of code. What am I missing?
Edit: I suspect the author may be talking about all software on the a/c. 6 million lines of control automation code seems like a bit much. Nevertheless, when the code is in millions of lines, the control automation is attempting to go well beyond simply assisting the human pilots. If the author is to be believed (and I see no reason not to), at some point in the last quarter century, the roles on the flight deck have reversed.