为什么美国人写的英文那么晦涩难懂？

为什么美国人写的英文那么晦涩难懂？
请看下面这一句话，When I got to the end, it didn't even seem to try, content to let us wonder why
this 1960s version of XCOM didn't bother to tell 2010s XCOM (of XCOM: Enemy
Unknown) that hostile aliens exist and that there's a closet full of working
plasma guns somewhere.
这句话求解