[stcredzero]

(uninterruptible moves, for instance)

I bet this was done to decrease the complexity of the script flow. Otherwise, you'd have to provide for the interruption cases.

[psykotic]

I asked the blog's author and he said hits do interrupt scripts. Aside from that, more complex scripts intended for higher difficulty have explicit conditional branches after moves to allow for blocking and counters. The triple fireball script example is for "easy Ryu", so it's intentionally dumb/non-reactive.