Whenever I see a small comment like “C++ bad, X good” I wonder if the poster has a thorough understanding or they just hold the opinion because it’s fashionable since they heard it so many places prior.
Heartbleed was reviewed twice by literal OpenSSL experts and security experts who were specifically looking at it to determine whether it was a security vulnerability or not and concluded (incorrectly) it was not. And now it's the poster child for bad software bugs.
It's really hard to write correct software in any language, and time has shown again and again that memory safety is just not something you can hope to do without if you care about security in the slightest.
I think possibly "perpetuating the fear" was the intent. I'm not siding with OP as I don't use C but if they think it's a bad choice then they probably want to assist other people in avoiding that choice.