Anyone paying $5m for a gold card will have a higher standard of living in the US than Thailand or Vietnam. Even if you make just a bit above the US average salary your life will be better in the US than Thailand at least. In Thailand from my experience living there it is great if you're broke/low income but actual luxuries are a premium to western countries.
Why would you expect someone to be spending all their money on this? It's clearly for wealthy people. I'm Canadian/Australian so you can probably guess my opinions on Trump and the current US government but I don't have any problem with this type of program and most countries already have a similar one just at a lower price point(I think Canadas in like $2m in venture investing instead of a straight payment to the government but same difference).