My experience with H1Bs is that they don't have any ethic for excellence. Their ethic is based on "good enough" or "slip one by". It is an ethos ingrained in them since childhood.
They take pride in their ability to "get over" and slide through life. Unless someone is looking over their shoulders, you can bet the task with be accomplished will minimal thought and care.
Your experience is the same as my experience. And they hated working for me, because they don’t respect women.The fact that I checked their code and made them redo it if it was slip shod didn’t help. Had to be tough with them.