Honestly man... Your pure instinct is just horseshit. Cos, you don't know what I know, so its funny how you say that I know sack shit.
Yes, they do all their best they can, but let me say this for you mate that those people who killed those 29 people, weren't probably checked before they entered into country or something, so its still realistically government fault or more so the security fault.
Therefore, its fault of security to fail to follow the security protocol.