And how many genuine threats have you detected using an A/V scanner?

The tipping point for me that made me uninstall all virus scanners was when I realized that:
1- I had no way to let it understand my own code was not hostile.
2- They fail to detect in time some of the most dangerous threats nowadays, such as password sniffing rootkits.

Not really, because then the expectations are lower. It's actually much harder to impress others and compete when you have a lot of things already at your disposal.

Besides, it's not like you can use much, desktop systems don't come with such useful libraries, or APIs written in the spirit of reducing the amount of setup code required.

A/V scanners are just too fucking stupid to see past the fact the executable has been compressed.

No extra download on top of a fresh installation of your (proprietary) OS.

On linux, it's much harder to define what's in and what's not, so it's a genuinely less interesting playing field for competitions.

It seems to me you would also forbid a demo to use a 3d accelerator in the name of having a metric you can understand.

That's alright, but that's not really pushing your hardware to its extents.