You have different catagories of women (i say women because it is them who get pregnant)
Firstly, there are women who are left over with issues from childhood and are constantly searching for something, some have babies (a family), thinking that is what they want as nature and nurture programs us that way, they don't have the insight to their problems or how to help themselves.
Then there are the women who are 'mismanaging' everything, including contraception.
Women under stress and accidents do happen.
Some don't think to deeply about anything, have any insight into anything, including the quality of care that they are giving any aspect of their lives.
For others their children are the only thing that is worthwhile about them and that they have (in their opinion, not mine).
Of course there are the women with, MH, LD and addiction problems, lack of self esteem, etc.
Then there is a lack of 'intelligence', including emotional and common sense, for want of a better word.
I think that there are very few who are happy to make their lives and their childrens lives unhappy, on purpose.
OP- i agree that the excuse making should stop towards some, suggesting contraception isn't being judgemental in the extreme cases that you have mentioned, it is being sensible.
I think that it is similar to DV, when you stop making excuses why people stay (or continue with behaviour) and take a empowering approach, it is the only way to help.