This is the exact attitude I'm baffled by. This is only true if you only have USD to buy with, and you're only interested in selling in USD.
If (say) you have a bank account full of fast-depreciating GBP, and you decide you want to buy gold, then later sell, perhaps to buy a house (priced in GBP), then then *only* price which matters is gold in GBP, at the time(s) you buy and the time you sell.
It seems to me that (unless you want to trade the swings in USD) obsessing over the price in USD is just a distraction for those not buying/selling in that currency.