Sexism doesn't require sexist intent. A firm in which all behaviour is expected to rigidly adhere to a particular standard pattern, irrespective of gender, may still be sexist if that standard is normal for men and requires effort to achieve for women.
What kind of patterns are you talking about? Could you give an example of this, plus a proposed fix?
Ok, let's a take a firm that values a number of personal qualities. It values dedication to the company, the ability to get on will with people at work, people who will stand up for what they believe in, drive change in the company, has a calm and consistent demeanour, shows personal modesty and refinement, and gets on well personally with the director. All good stirring stuff.
Now let's supposed that they measure dedication by long working hours and a willingness to stay late at short notice, and that they measure the ability to socialise by how willing you are to go on a night of hard drinking after work. That 'standing up for what you believe in' involves participating in dominance contests with other managers and petty points scoring, drive change means being aggressive with others to get what you want, that the company's lower hallway has floor mounted heating vents, and the upper hallway has a glass floor, and that the director spends his lunchtime at a strip club.
So what you end up with a firm that systematically discriminates against people who have family or childcare responsibilities outside work, don't have a large capacity for alcohol, are well practiced at otherwise pointless dominance contests, is aggressive with others, wear dresses, and don't enjoy titty bars. Perhaps unsurprisingly, women don't do very well in the firm. But the problem isn't that the men in the firm personally dislike or personally disfavour women in some way.
(Now that I'm in front of a PC and can type a full reply
What you have described is a set of criteria that is partly reasonable, and partly unreasonable and sexist.
It's reasonable for a firm to reward employee who make personal sacrifices such as working late at short notice, because the company can benefit from that;
It's unreasonable for a company to reward employees for partying with the team after hours;
It's unreasonable, and even stupid, to reward petty displays of dominance and points scoring;
It's reasonable for a company to value aggressiveness on the condition that it is channelled into something beneficial, like winning a sale or sorting out an unco-operative supplier, rather than bullying fellow team members;
It's reasonable to have floor vents that blow up hot air; it's unreasonable to prevent women from wearing trousers to work in the same office.
Same goes for glass floors (tried doing a few Google searches to find an image of that kind of architecture, but couldn't find any examples of this).
And lastly, I'm confused: who, besides the director, is expected to enjoy the titty bar? Is the implication that he conducts lunchtime meetings there as well?
Some companies, such as Fuji Xerox, have found that flexible, generous working arrangements (Flex-Time) for their staff results in higher productivity. But this is not necessarily true for all businesses. It's not sexist to reward personal sacrifices by your employees if it can be shown to boost productivity. The fact that more men than women are able and willing to be that kind of employee doesn't not mean that the company has a moral imperative to change it's business practices in order to bring in more women.
Getting back to your original point, now that you've clarified your meaning. It's rarely correctly to describe something as normal for men and difficult to achieve for women. Both men and women are diverse groups; it is more correct to talk in terms of how many people from either sex can do something. For example, more men than women can lift a 25kg parcel, which means that more men than women can work as couriers. Using a non-gender example, Asian men are less likely to have the height required to play élite basketball, but it is not reasonable to call recruiters racist for that.
Your example highlights that standards which have a disparate impact on each of the sexes are not necessarily sexist, although they often are because those standards are unreasonable and unjustifiable.
Taking into account though that I have lived in societies where sexism targeting the female gender was overt and obvious and basically institutionalized as a "norm". Living in Campania for 6 years (region of Naples, Italy), the local traditions and culture were extremely sexist. It remains a male dominated culture with a huge dose of "machoism". However, in Sicily, the "nonna" or eldest female (usually grand mother though it could be a great aunt) is highly respected as the matriarch. But she is still the typical homemaker, the one who passes on recipes and trains the younger women into the "art" of being a good and subservient wife. Very often in sexist societies, the elderly women are responsible for perpetuating traditions which cause the stagnation of younger women into a very limited and narrow minded gender role. A role dedicated to please and serve men and..... don't they dare not be happy in that role!
[a case where "not all women" disclaimer is appropriate I guess ...]
