Sorry i haven't read all the comments. I may well get flamed for this but here it goes...
Speaking from experience and as an employer. I don't care whether the person applying is a SAHM/SAHD/single/married/disabled etc. What I need is someone that has the skills, experience or the ability to learn quickly (dependant on the role) and all that stuff people read on job roles/profiles. In my field up to date knowledge of whats happening in our industry and flexibility is important and it does impact decisions on candidates. This is not discrimination, we have to make decisions that secure the companies future and inevitably protect jobs and yes our bottom line. If we are not flexible to our client needs, we get sacked. If we get sacked by clients then this results in redundancies so we have to make decisions that are in the best interest of the business. This means we have to employ the most suitable candidate for the role regardless of gender, disability or a parent. That's RL!
With regards the gap in CV. Again I don't care whether that's due to been a SAHP or someone who went traveling etc. I care that I believe the person in front of me can do the job. And if our business had to choose between two people with equal skills/qualifications/whatever but one persons CV has a gap of a number of years (regardless of reason) and the other has continued employment, it's an easy decision. We can get the person with no gap up to speed and getting on with it quicker than having to up skill the other. Unfortunately it's a tough trading environment and companies are their to protect the profits, shareholder value and growth.
IMO, SAHM are not discriminated against and no one is trying to force anyone back to work. If people choose to have children thats a choice they make and the impact of choosing to stop working should be considered. And if it someones choice to stay home because they feel its in the best interest of their child/children then go for it but they can't complain when they don't walk straight back into a career after 3/5/10 years..