While what they say is on point, the majority of people making these memes are Slavs themselves.
In a on Slavorum, a website dedicated to all things Slavic, the author expresses concern that even good-natured jokes about people wearing fake Adidas and drinking cheap beer while squatting have the potential to do real damage by the way of spreading ethnic stereotypes, even if it is initially done with humour and no intention of spreading hate.
This is middle class hatred of the white working class, pure and simple.
Oh, don't believe the popular etymologies that you read sometimes in the press and on websites.