> Weird question to ask, that is pretty obvious.

For something the the prior statement it is never a weird question to ask of there actually evidence of this or just it seems like it should be true so we believe it.

There are tons of things that seem like they would obviously be true, but it turns out they aren't.

It’s not obvious to me because cyclomatic complexity is not a straightforward proxy for the number of systems that are being combined.

It’s also the case that some of the most common sources of vulnerabilities, such as SQL injection, introduce no additional cyclomatic complexity. Heck, buffer overflows are good for your cyclomatic complexity - those array bounds checks are all extra branches.

I'd argue that assuming something is obvious without any empirical validation is the root of a huge number of misconceptions that humanity has historically had. There's a reason science suddenly started moving a lot faster after we moved past Aristotle and started measuring things in experiments.