They differ in their degree of rapaciousness. The formation of a second-tier working permit system disadvantages both citizen labor and the permitted workers themselves. Slavery involves forced bondage and lack of choice. I agree with you that there is a disadvantage, but you can't just slap the label on any system. H1B laborers make median wage and can come and go at their leisure.

>seems kind of jealous of oil rich countries developing at a faster pace than theirs

Fascism can sure look pretty from the outside.