Where's the line?

After reading Ruth Hubbard's article about the discovery of DNA and our subsequent discussion in class, I've begun to wonder: where is the line between being scorned in academia due to gender differences and scorn due for other reasons? As the Hubbard article says, both Barbara McClintock and Rosalind Franklin's achievements were not really recognized until they were either very late in their life or deceased. And I think it's fair to say that a big reason for this marginalization is because they were women. However, is it also fair to say that they were marginalized for the same reasons male scientists that came before them were too? That they were simply too unknown or too young, as has plagued other eventual famous scientists? For example, in the Hubbard article, she speaks about the geneticist Gregor Mendel, who today is seen as the father of genetics. When Mendel published his work in 1865, there was little to no notice in the greater scientific community. It wasn't until 1900, 16 years after Mendel died that his discoveries were noticed by the broader scientific community. Gregor Mendel was a man, but his work was marginalized just like McClintock and Franklin's work, and just like Franklin, his work wasn't recognized until after he died. So I must ask, where is the line between being marginalized because of your gender rather than for other reasons?