It looks that way to you (I'm guessing, since I don't know a thing about you) since that's your frame of reference. While not knowing anything about Marston's private life, either, I'd also guess that his personal experiences with being submissive were of a kind when it was to "loving authority" who really did have his best interests in mind, rather than despotic authority who wanted to use him as tool for their own interests. More mistresses than slaveowners, in other words.
As for messages of empowerment in Wonder Woman, I think some scenes like that were posted recently.