Not sure how the long term exchange rate movements are relevant for most people who take a paycheck, spend a great deal of it, then use the rest to pay down debt or invest. Not many people are choosing to long term hold and deciding between dollars or pesos. And even if paid in pesos you could open a dollar bank account anywhere.

If you get paid in Peso you lose money every payday that you don't get a significant raise in salary. If you get paid in Dollars your salary raises roughly on pace with inflation.