“Why are Americans so bad at League of Legends?”/“Because they can’t defend their towers.”

A riddle about the multiplayer online battle arena video game League of Legends hints at the September 11, 2001 attacks on New York City’s World Trade Center:
   
Q: Why are Americans so bad at League of Legends?
A: Because they can’t defend their towers.
   
The joke was posted on Twitter on March 31, 2015.
 
     
Wikipedia: League of Legends
League of Legends (abbreviated LoL) is a multiplayer online battle arena video game developed and published by Riot Games for Microsoft Windows and macOS. The game follows a freemium model and is supported by microtransactions, and was inspired by the Warcraft III: The Frozen Throne mod, Defense of the Ancients.
 
In League of Legends, players assume the role of an unseen “summoner” that controls a “champion” with unique abilities and battle against a team of other players or computer-controlled champions. The goal is usually to destroy the opposing team’s “nexus”, a structure which lies at the heart of a base protected by defensive structures, although other distinct game modes exist as wel
   
Twitter
斯坦利‏
@stanleyjayfern
Why are Americans bad at League Of Legends?
Because they can’t defend their towers ..
4:31 AM - 31 Mar 2015
 
Twitter
bang bang, boom boom, pop pop‏
@HasaniDeGrote
“Why do Americans suck at League of Legends? Because they can’t defend their towers” wowowow
3:33 PM - 31 Mar 2015
     
Twitter
Jemmyt Reloaded‏
@JemmytG
«NORTH AMERICA IS BAD AT LEAGUE OF LEGENDS CUZ THEY CANT DEFEND THEIR TOWERS 9/11» J’avoue qu’elle est pas mal 😉 #TwitchChat
8:18 AM - 11 Apr 2015
 
Twitter
Leo Emmanuel‏
@leosombiro
You know why americans are so bad at league of legends?
They cant defend their towers
#NeverForget
1:55 PM - 1 Jul 2015
   
Reddit—Jokes
Why are Americans so bad at League of Legends?
submitted September 8, 2015 by Fawskeen
They can’t defend their towers.
 
Twitter
Christian‏
@ChristianB_CJ
Why are Americans so bad at League of Legends?
They can’t defend their Towers.
2:20 PM - 8 Sep 2015
   
Reddit—MeanJokes
Why are Americans so bad at League of Legends?Sigh… (self.MeanJokes)
submitted September 11, 2015 by [deleted]
Because they can’t defend their towers.
 
Twitter
Winnwell‏
@WinnwellShow
Why are americans bad at League of Legends? ‘Cause they can’t defend their towers. Happy 9/11 Bring your plane to work day.
2:55 PM - 11 Sep 2015
 
Reddit—Jokes
Why are Americans so bad at League of Legends?
submitted December 12, 2015 by _Kyu
because they can’t protect their towers
 
Reddit—Jokes
Why are Americans so bad at League of Legends?
submitted November 27, 2017 by BondChance
Because they cant defend the towers
COMMENTS
MaxEatsDonuts
This joke is litterally said in Twitch chat at every League tournament in which NA participates. I expected something better OP