Why is it that so many burger places have thousand island dressing as the standard condiment?

Then they act like not only are you crazy for not wanting it in favor of ketchup or something else, but also like it is way too much work for them to leave it off.Why is it that so many burger places have thousand island dressing as the standard condiment?
I noticed this when I was in the Philippines. I had a terrible time trying to find regular MUSTARD in any restaurant. Just give me my mustard.
Because it's a combination of mayo and ketchup so instead of putting two separate condiments, it is two in one and standard to have on a burger. Same with if you like tomatoes or ketchup plus mayo in your sandwich you can just use thousand island instead to combine the two.Why is it that so many burger places have thousand island dressing as the standard condiment?
TI sauce if for those who can't make up their mind if they want ketchup or mayo on their burger, so they put both. As far as leaving it off, well those brain cells needed to comprehend that difficult idea were sloughed off during the last french fry deep frying session.
Possibly because the regular ole Mayo that they put on most buns to begin with has gotten old !?! rather it has been overly done or used by many other burger joints !?! ha ha ha So I guess someone came up with putting just a slight twist or taste on the standard Mayo used on many s0Oo.`called delux burgers !?!. r'`R`'r
I don't know - this is a very good question.



I think maybe it started with McDonald's and people just copied it.



It sure tastes good though.



I would like to see what other people think.
what burger places are you talking about?