Mine also does respond to all pings if they are directly to it.Fair enough, I guess.
My asus router has no issues with the frequency of ping signals sent, and I would still consider it a matter that should be investigated. I'm also wary of those who use terms such as "bad networking mamba jamba", but concede the author might simply not want to get into great detail about the subject.
I've been asked to look into a packet loss problem a previous consultant identified at a client. They have two ADSLMax connections, one for data and the other dedicated to VoIP. The packet loss isserverfault.com
And I'm still not convinced that the "issue" is an actual issue outside of "omg, the graphs look different", but I will concede that fq_codel does appear to perform slightly better on your network.
If I leave ping running directly to router with 0.1s interval while I run another to 18.104.22.168 concurrently I don't get any packet loss on direct ping to router, yet it shows in the ping to 22.214.171.124 but doesn't carry to the final destination.