I don't think that website implies what you're thinking. The only significant thing that happened in 1971 is that Nixon suspended the convertibility of the dollar into gold, giving the US leeway to run unlimited deficits, paying for imports with paper.
Now, America wants to reduce its debt and curb industrial powers like the EU, Japan, China, etc. but it doesn't want to give up its exorbitant privilege that got it into the debt whole in the first place.
No, your point doesn't stand at all. It's completely baseless. You took a detailed resource referencing America's departure from a gold standard and you're twisting it to support your pet immigration policy.
Now, if you want to limit non-European immigration, it's a personal opinion and you have a right to it, but you can't make a blanket statement that, "everything worked better," or misinterpret data to say what you want.
Don't pretend you're being data-driven when you've made up your mind and now you're trying to torture the data into saying what you want.
What metrics are you measuring by?
So, while it seemed like you were trying to argue logically, it appears your argument is: I don't like non-Europeans. And you're trying to massage the data into showing your opinion is data-driven because it can't stand on its own merit.