We had three Bulgarians working for us over about a five year period.
A qualified Vet, an Engineer and a Farmer. They were never late, never took a day off sick and never missed a window.
Every day one of them (the farmer) thanked me for employing him even after three and a half years!
They actually enjoyed being at work, and would often stay after their working day to help with little jobs around our workshops, not for any extra pay but because they wanted too!
Their whole work ethic is different, they didnt consider being at work just somthing to get money.
It can only be cultural, it would bring shame on them not to work, the same as it was here up to the early 70s