Military service in Israel is mandatory and the conscription rate in the core "educated" areas is ~90%. Each year, the intelligence corps then gets what is practically* first pick of the best minds of that year (typically kids who are already skilled in programing). They then get to have them for 4-6 years meaning unlike modern employers, they have time and motivation to invest in training them. Then you get the most apt programming minds of a generation spending six years together learning and building connections with each other in core programming and security skills.

Imagine if all the ivy league graduates in the US would be forced to work together for the same company, for free, for 4-6 years. Would you be surprised if suddenly former employees of that company found ways to become very successful in business?

* - Technically they get something like 3rd pick and there's negotiations and it depends on what sort of roles are involved etc. In practice, conscripts have some influence on where they'll go and if you have a choice in any role in the military, you are going to pick "write code in an air-conditioned office" over any other available option.