Akira Nishitani is one of the developers who worked on the original Street Fighter 2, which is still used as a blueprint for the series today. It birthed many of the mainstay mechanics, including that of blocking. Believe it or not, Nishitani says the idea of blocking caused quite the controversy back in the day, even if nowadays it seems like an essential inclusion.
"So what I was told by others was, 'So... if you block, you never die.' You know the shooting game R-Type. It has something called 'Force,' which basically makes it invincible to attacks. So people told me, 'Oh, it's like that? So, you basically never die?' And I did think it was dangerous too.
Those who win are those who are good at blocking. Ever since the mechanic was incorporated in 1992... It's profound. Because if you only block, you're just weak. But here and there, with block, you can deal with things without losing health. My impression of fighting games is that if you're good at blocking, you're strong."