While that might be ideal for the kids, no kid has a right to a stay-at-home-parent.
A divorce results in the creation of an additional household and changes the finances of the entire family drastically. I think placing the entire financial burden on one spouse is unfair.
If he agreed to her being a stay at home Mom , he took on that responsibility. He should comtinue it till the kids are old enough to not need a stay at home Mom.
Also most stay at home Moms dont ask for a Divorce unless they catch the old man sneaking around.
IMO most divorces come from women who are working and looking over the available options. These women should not get alimony.