The history of Santa Claus is as american as apple pie. The retooling of various european folklore elements starts back around 1830 (in manhattan?) if I remember correctly... that's where the sleigh comes from Certainly coca cola did not invent santa claus (that would be an urban legend) but the modern iconic image crystalises in its advertising in the early1930's.
https://americanhistory.si.edu/blog/santa-coca-cola
In the early 1930s, Coca-Cola turned to Haddon H. Sundblom, an advertising artist with the D'Arcy Agency, to design a new Santa. Sundblom redrew Santa Claus as a plump, cheerful man with snow-white hair and dressed him in red and white—colors that had already become associated with Santa, but which happily matched Coca-Cola's signature colors. Sundblom even provided a Mrs. Claus, based on his own wife. Today, it is Sundblom's Santa who decorates everything from Coca-Cola cans to Christmas sweaters, from greeting cards to home décor, all because Coca-Cola wanted to increase its winter sales.
Seem to remember that there was a lot of debauchery around xmas time back in the earlyish 1800's which would certainly inspire a puritan opposition to the whole notion.
This is false, as Reelya already expounded upon. The only traits of the modern Santa that differentiates him from 19th century Santa is the red and white colours look, which predates Coca-Cola. The whole fat, white-haired, bearded and jolly parts are all traits of the 19th century Santa as well.
Here are some works from late 19th or early 20th century by Jenny Nyström, the cementer of the image of the Swedish Santa equivalent, "Tomten", where you can still see the clear house elf origins, exhibiting all of those traits except maybe excessive rotundness:
I also strongly doubt the sleigh comes from anywhere. Sleighs are just how people got around in winter. Everywhere.
Why do people care about gender, especially gender roles? Why are gender roles so ingrained, especially in conservative regions? Why do people bother with them if (to my heavily-biased understanding) all they do is limit what people can and can't do, causing them to be unable to express themselves however they want?
Because norms for behaviour and expectations are tied very closely to what people consider virtuous and what gives you social clout and repute.