And all developers have to start somewhere. Look at the first games BioWare and Epic worked on. They weren't exactly stellar titles.
Killzone, despite it's flaws, had a lot of cool ideas. The reload animations, the use of motion blur, so many things that Guerrilla wanted to do with Killzone 2 originated in Killzone. They just lacked the time to polish the game, and more importantly, lacked the experience to truly get things right. There were just some bad design choices, like the weird jumping system.
You have to remember, Guerrilla Games is the first real development studio in the Netherlands. For many of the guys at Guerrilla Games, Killzone was their very first title, for some their very first job!
You can read more about the history of the team here.







