I do not know her situation, but even I can tell that you are making assumptions based upon your own situation.

There is absolutely no way you could estimate that her ex is paying 1/3 of his salary or that the payment is any burden on him. Do you think 2k would be excessive support for a multimillionaire? I mean, seriously. You have absolutely no clue how much her ex is making or has, or how much of it is being given to the support of his children. It could be no more than 10% for all we know. Is that excessive?
You have no clue what a person is doing to cut costs in raising their children. You are making assumptions. Also, "have mom watch the kids".... again, are you serious? Why should grandma be a free babysitting service just so that "daddy" doesn't have to support his kids? They aren't grandma's kids. To be honest, I think it is asinine to think that a woman can fully support multiple children on 25-30% of a man's net income, yet he is unable to support 1 person. You claim that the money is to support the kids, not the mom, but really.... she is fully able to support a family on (under 2K) + her own income, barely, while he lives in a tent making more than that? Again, are you serious? His student loans are not her problem anymore than hers are his problem. No one is expecting him to pay her loans or any of her expenses. It is about providing for the children. You are right, it is not alimony, and no one has ever insinuated that it is except for you males who think 25% is excessive. If he is in the poor house it is not because of the 25% he is giving for his children. It is because he is not able to manage the remaining 75% that he lives off of.
Mortgage must be figured into expenses to raise a child. Do you expect her to live in a one bedroom, one bath studio apartment? Again....... are you serious? You don't think he should help pay the extra mortgage it costs for her to have a place large enough so the child(ren) can have their own room? Maybe you can give her one of your $12,000 a month tents.
If you want to nickel and dime what expenses come solely form the kids, that is fine, take the difference in mortgage, divide by two, and include that figure is his obligations. Don't forget utilities for the bigger place..... again, take the difference and divide by 2. Don't forget to add in half the gas for all her carpooling that she does for their activities. Oh, and activity costs, silly me, how could I forget that? Half. How about clothes for school? Half. School lunches? Half. School supplies? Half. Food? Well.... take the total it costs, subtract out her portion, then half it. We already mentioned day care. How about all those birthday parties the child attends and need to buy a gift for? Half. Doctors appointments? Half. (Often both are obligated for half of any out of pocket expenses, co-payments, etc.) Toiletries? Half. The list goes on.
You do not have to believe the media (or research rather) on how much it takes to raise a child. (The above website, for the record, only estimated $180 a month towards the housing portion of the child...... but then, you think that is excessive. Stick them in a one-bedroom studio.

) You do not have to believe the research that shows it is women who suffer financially after divorce, not men. You do not have to believe anyone or anything, but it still does not make anything you say right. You can not show one thing to back up any of your claims..... and if you did find something it would be a single case study-- nothing more.
I am aghast that a man claims he is barely able to survive on $80,000+. We support a family of 7 on less than that, and we live very comfortably and lack for nothing.