All "Natives" to any area hate seeing people be tourists lol. I've never seen any biggotry towards foreigners though, at least not to their face or so they'd notice.
Working in a restaurant for 5 years though, I can tell you that the biggest gripe waiters/restaurant staff have with foreigners is that they stereotypically do not tip well. In America, restaurant workers are paid very very little and are actually working for tips. For example, at the restaurant I worked I actually made only $3.25/hr, which if I worked a standard 30hr work week I would get a check for $0.00 that said "Void" because all of it went to taxes

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A little tip (pun DEFINETLY intended) is take the tax of your bill, round it up and double it. This is the absolute MINIMUM tip. So for example, if your tax total is $8.06, then the tip you should leave should be equal to at LEAST $18.00. This is considered a "fair" tip, but something along the lines of $20.00-$25.00 would be considered a "great" tip for that bill.
If that seems "high" keep in mind that wait staff do not keep all of their tips, they usually have to give a certain percentage to the buss boys, bartenders, etc. The percentage they give is usually based off of the subtotal, so if the tip is really small but the subtotal is high, waiters sometimes wind up PAYING to serve you since they're still obligated to give that percentage to the other staff based off of the subtotal.
Given that $18.00 dollar tip from above, the waiter probably only keeps about $12.00 or so. If you get a check that has the "Gratuity included" in your total, you should still leave a few dollars on the table as that gratuity that was added is usually on the border of a "fair" and "bad" tip lol.
Sorry if this seems kind of long and pointless, but after 5 years in the restaurant business in a tourist town I've been burned waaaaaay to much by foreigners lol. I once got a $5.00 tip on a $199.00 check....the tax was like $10 something. Yea, I wound up losing a a lot of money in my tip out
P.S. - I'm from Long Island, NY about an hour and a half train ride from New York City. New York City is FULL of tourists from all over the world, you'd fit right in lol
