@matigo It's definitely a personal grudge. From an article where Nir Zuk was interviewed back in 2010 [itworld.com]:
First, the engineering department in Israel grew very quickly, from a few engineers to a few hundred. It became very bureaucratic and it was impossible to do anything. They were focusing on fixing bugs instead of developing new technologies, and I like to develop new technologies. So, we started a small engineering group here in the United States and we built a product called Floodgate, a quality of service product which Checkpoint started serving, and then in 1998 we had a complete implementation of a bandwidth optimization product. The product was ready to be released, and then Checkpoint decided not to release it. The reason given to me for not releasing it, was that the engineers in Israel were really angry that someone in the US was having fun building new products. I'm not kidding you, that was the reason! Then I said, okay, this is an organization that I don't want to work for, and I left that day.
Check Point killed his baby. As a result, he wants to kill Check Point.