I would presume that "making motherhood more attractive" means for those who would otherwise choose to, but are dissuaded by the treatment of mothers in the society/culture in which they live. If I was a young woman in the UK in the era where you were expected to be married before having children, and to give up work entirely on getting married or having children and rely on a male partner, then I might not have chosen to have a relationship with a man and have children in that environment. Especially if access to birth control and abortion was restricted or unavailable altogether.
It's not wrong for women to want to have children, or to want to have a fulfilling relationship with men if they are unavoidably heterosexual and a fulfilling sex life. Nor is it somehow anti-feminist, or a weak choice that only happens because women take part it it unthinkingly.
If you are faced with a rigid social system that looks unlikely to change in your lifetime then I can see the appeal of these 4B movements.