Why Isn't This Standard - Visitor's Tax

There are a lot of countries out there - just look at a map.  Many of these countries have special monetary deals just for being a member of their country.  Discounts are offered on everything from food to alcohol to cars.  From the extensive research I have done (none) to the many experts I have talked to (two friends), it seems African countries are the ones that are perpetuating this scam.  It sounds like a joke, but a vacationer and a local walk into a bar, order the same drinks, and the local will sometimes save 90% (in Eritrea)!!!!!!!!!  This would seem like a genius way to raise money for your country without stealing it (taxes) from your citizens.  Where can you think of that has an economy that isn't so hot and needs money but doesn't want to raise taxes?  Who would complain?  It's a no-lose proposition.

Other countries also charge a departure tax.  Don't know what that is?  That's a tax to LEAVE their country.  Can't pay to get out?  Then you will have to pay to stay in.  I have paid $50 for this luxury.  Another huge profit generator.  According to the internet, over 50 million people visit the US every year.  I say we charge them $20 each for the trouble of stopping and giving them directions and furthering stereotypes.  That is One Billion extra revenue a year.  BOOM.  Done.  Do I want to be president?  Not really, but everyone says I should be with all these ideas.

America must do this.  You appease anyone not wanting taxes raised and you appease anyone who wants to deter foreigners (the South).  Who doesn't fit into those categories?

"I only accept cash up front for directions, you Frenchy.  You don't like that, then my sister/wife here will give you free directions to Hell."