I have a number of patents revolving around this specific issue, and I can tell you certainly this guy has no idea what he is talking about.

First, let me preface this, the language does matter, but the larger complications revolve around the operating system. Most transactions have a hard real-time deadline of 20ms or less. JVM creates additional issues on top of what are already present from the OS. If you're on Linux, a real-time kernel is required to handle these transactions.

For Windows, there are asynchronous methods you achieve this functionality, it is possible, but very difficult to do.

After reviewing this guys LinkedIn profile, all he has ever done is Java. He is a Java advocate. I think Java is great language, but this is one place it doesn't belong.