Are the parents of EU blue card holder eligible for family reunion Visa?
score:2
Accepted answer
Β§36 AufenthG says that an Aufenthaltserlaubnis may be granted to parents of a resident in Germany if not doing so would be an undue hardship. Β§36 ("kann", "may") is much weaker language than e.g. Β§30 ("ist ... zu erteilen", "shall be granted").
There are special rules when the resident in Germany is a minor refugee without any other guardian in Germany. Presumably a blue card holder is older than that.