Some see having quotas for women or others as being a free ride, instead of being based on merit. It is not. They are about finding out what is stopping them achieving the number of positions that represents their numbers in society.
Women are half of the population, yet they are not present in those numbers in leadership or managerial positions in many industries. Of course, it would be counter-productive to just replace men with any women to make up the numbers. A person has to have the abilities and skills required by the position to carry it off.
What many critics forget is that, far from women now being supposedly equal, they are still being systemically discriminated against in attitudes and expectations, and these close opportunities to them. When testing shows that just changing the name on a resume from a female sounding one to a male one dramatically increases the chances of getting an interview, we know there is a long way to go. And this is before they get into the career ladder, where more biases await them.
In this climate, quotas are not set as a fixed 'must be', but a realistic target percentage to aim for. They are the first step on the way to equality.
Getting to those targets involves finding and removing systemic biases that thwart advancement. This combines education and performance evaluations that favour even-handedness in expectations and treatment of all people, regardless of their gender, skin colour, or other such classifications basically irrelevent to their performance.
The other end of the discussion about quotas is about where detractors are coming from, especially when it's obvious that they know very little about what quotas actually mean in practice. They seem to be making a cheap emotional play to pander to those who feel disadvantaged, obstensibly by society, but usually by their own inability to change themselves and their circumstances.
It is easy to lay blame for one's circumstances at the feet of somebody else, and another to be the one who is doing something worthwhile for themselves. Blaming others will not change your life, but just attract those who, instead of being your 'saviour', will try to manipulate you for their own ends. Wake up to being the champion of your life, by changing yourself to be better, so making your life better.