Just picking up on a point here..
"... what is it that makes the USA appear so culturally hollow"
There are two aspects to this. Firslty, the combination of 'culture' and 'hollow', and secondly, the non-American world's perception of America. Let's look at the culture bit first. What do we mean by cutlure?
There is a scientific answer to that, but for most people, I think 'cultutre' is about vibrancy in eveyrday life. 'Cultural' places have character, something that stands out, is interesting, intellectual or lively. Boring, purile, trite and inane people, places and conversations are seen as 'not being cultural'. So, one could say that 'uncultural' (sic) America is perceived as boring, inane, asinine, trite.....
Here's what amuses me. Yes, by this definition, America's cultural advancement is comparable with the economic acheivements of Stalinist Russia. TV in particular is a moribund, oh so atrocious, scene of artisitc carnage, where moronic 'celebrities' pander to the whims of low minds. Jerry Springer and Oprah Winfrey don't so much spring to mind (pun intended), as run amok like a bull in the proverbial china shop. But what of programs of the quality of the Simpsons? How about South Park? Who here is a Trekkie? aka a dateless wonder
(joke)
America's cultural influence is virtually all pervasive in the areas of music, TV, clothing, fashion (also known as paying through the nose for a 1 inch label on the collar of your shirt, in the hope that other people will perceive you as a better person)... How can America be culturally hollow when every culture on Earth is represented in the US population?
From Afro-Americans to 4th generation Irish, to Russians, Slavs, Greeks, genuine Irish (ie from Ireland not just Irish because great-great-great-great=great grandfather Paddy once bought a pint of Guiness)
, America incorporates every culture on Earth. This is a good thing.
I think that some people view America as a land of obese, stupid, ignorant, arrogant, loud, obnoxious idiots. Many of these words could be applied to some of the population of America. Some of these words could be combined, and applied to some of the population of America. Maybe even all of these words are true of some Americans.
Despite all these negatives, there are some points to bear in mind. My little list of negative terms don't apply to all Americans, or to any American in particular. Also, even if all these things are true, this does not preclude the possibility that there are some good things about America. Nor does it imply that everywhere (or anywhere) else is perfect.
This should all be common sense. Then again, if common sense really was common, lots more people would have some sense.
Back to the original question. Why is America perceived as 'culturally hollow'? Let me ask this: why does anybody perceive America as 'culturally hollow'? This blanket perception leaves no room for variance, and varity is America's greatest, and last, defence against many of the evils staining the world at the moment. True, there are shallow, idiotic, misbegotten Americans. This is true of many countries. These people live lives that amount to sleep, eat, shower, work, eat, sleep, shower, work, eat, TV, sleep, weekend, drink,sleep, shower, sleep, eat... ad nauseum.
I think that some people assume that this type of persona describes the majority of Americans. Maybe it does, maybe it doesn't. How many other people also fit this description? I think it's way too easy to hold... not an anti-American viewpoint, per se, more of a harmless contempt towards all things American. This makes people feel good about themselves, IMO. While America is far from perfect, and there is a section of the population that is shallow, I think it's going too far to say 'America', as a country, is 'culturally shallow'.