Andrew Nevins on "Ability to hack WordPress"

I'm really not sure if this is the right place to pose this issue, but I'm having a debate on another forum regarding the security of the fundamental code associated with WordPress.

There's an Australian site called Whirlpool dedicated to many subjects, but very much into IT related subjects. Every time that someone raises a question about WordPress, a number of 'experts' pipe in and claim that WordPress is the most insecure publishing system in existence and make every effort to discourage its use.

A recent such thread was raised and one pundit responds to my question:

So you're saying that you can hack any WordPress site in existence?

Yes... Word for word that is exactly what I said.

https://forums.whirlpool.net.au/forum-replies.cfm?t=2546167&p=-1&#bottom

Is there an authoritative way in which such statements can be rebutted?