Where does that inherent sexist bias come from?

 I just finished reading this book. I have no idea how it came about to be in our home. Anyhow, I picked it up, saw that the author was an IIM-A gold medalist, who wanted to talk about 18 principles of life he had picked up over the years. Sounded good. I started reading the book - again, the broad principles sounded about right. It was also an easy book to read -  no long drawn gyan, no unnecessary anecdotes - they were simple fundas which we all have come across in life and probably know inherently, even though we forget to apply them some times.

Then as I got deeper into the book, some elements of a sexist bias started creeping in. There was this section on being professional, if I remember correct, which spoke about how a woman who could manage a career and home both was more professional than a woman who could only manage her home.

Now I had a problem with this two ways -

1. Whatever happened to personal choice? 

I am all for women working and being professional leaders etc, but does that mean that a woman who chooses not to is not "professional"?

2. Why can't a man decide to stay at home and not be "professional"? Not my concept of professionalism, these are the author's thoughts.

Similarly, there was another reference somewhere later in the book which spoke about women managing the kitchens while doing other chores - the chapter was on multitasking. Now I know this is true in most households, but at a time when we are really trying to avoid gender stereotyping, I thought this was something which could have remained neutral.  It could just as well have been a man multitasking including managing the kitchen. Obviously, this was again probably something which was part of the inherent thought process of the author.

Now I am not here to do a book bashing. It is just incidental that reading this book brought forth these thoughts. I also remembered this post on LinkedIn which spoke about gender stereotyping through another story - a man going for his first interview, his father driving him down, and him receiving a call during the drive from the CEO of the company wishing him luck, and addressing him as son. Most people who read the post for the first time jumped to the conclusion that it was a pre-recorded message. They never thought it could be the guy's mom. Again, they probably did not also think it could be his other dad, but I think that's another issue which needs a different post to really do it justice. 

So my question is, even with the most educated of the lot, what can we do to move towards more evolved thinking?