I'll try. First I want to make sure that this is from my personal, but vast experience. I'm not saying it is the only way to get a good job, but it is the best bet.
I think the most important reason is that Israel is a small and a tight knit country, and so is the startup scene. It helps that the huge majority of talented developers served at very specific army units (the most famous is 8200). This leads to a simple truth - when I interview someone he was probably referred to me through friends or at least I know someone who worked/served with him.
When I read the article I found it funny that Amar was OK with working for free for a few months. Me and almost everyone I know served at least 3 years in the IDF which is pretty much working for free.
Could you explain why?