I don't think that is true, since the publishers knew the identity of the authors (as far as I know). And there are some examples of women authors being very successful (e.g. Harriet Beecher Stowe).

It is more likely they used a male pseudonym because they didn't want prejudice against women and women literature to affect reviewers and readers, and/or they wanted to protect their privacy (and reputation, if they were writing about scandalous subjects).

I'm sorry, I don't know what you're asking? What does "that" refer to?

In any event your question is probably answered in the article (and if not, do further reading) and I'm not an expert on this subject, so what I "really think" is unimportant.