From Why can't I ping my freshly set up amazon web service EC2 instance? it seems that the architects from Amazon's AWS have chosen to block ICMP by default.
Is there some official source stating their reasoning for that? I assume it is because of security but I'd like to be able to read their official stance on it, if possible.
That’s a bit of a misunderstanding - only inbound ICMP Echo is disabled by default and you can allow it in your Security Group if you need to.
ICMP is a whole suite of Internet Control Message Protocol packet types, most of them used for various traffic flow controls, etc. Those are not blocked because they are related to other traffic initiated by the instance. Only ICMP Echo is blocked by default because you don’t have control over who pings you and there is no need to have it enabled.
The reason is simple - AWS won’t let any unsolicited external traffic in unless you explicitly tell it to. And that includes ICMP Echo.