Yeah, well, I don't think that math adds up. It's just an excuse without much thinking going into it.
Subsidized living from either state or private sources (unions, associations, mom, ...) can do that to both people and math: it warps them and their perception of the world.
Where I live, 20 rolls of 250 sheet TP (5'000 uses if you're stingy or doing your business as an employee of a Japanese firm) cost you, what, six bucks. A single package of 50 wet wipes (50 uses of smearing poop all over your butt) costs about the same, and that's not the fancy ones. So, yeah, the math don't add up and logic is weeping in the corner over there.
If a young mother does not have five bucks for toilet paper, I must ask: Does she smoke? Does she drink? Does she use recreational drugs? It's funny how people that don't seem to have enough money for the really basic stuff always seem to spend a lot of money they don't have on things they don't really need.
Wet wipes are wonderful for the finishing touch of our number twos. It's amazing. For number ones, it's not that cool, especially for ladies, as you tend to just enrich fresh wee with the smell of chamomile while you distribute it all over your nether region. It's already been pointed out, but wet wipes don't soak up anything, since they are wet already. You use them on a baby because a baby is usually still a human in the works, not able to use the lavatory properly. You use wet wipes on babies... as you use powder and oil and whatnot so the little buggers don't get sore and make life living hell for little baby, you and everyone else within hearing range. Wet wipes are part of a set of tools for a specific purpose, wet wipes are for finishing touches - they're like the torx screwdriver or little slices of white truffles on your carefully whisked egg yolk sauce on delicately thin and well refined self-made pasta.
Wet wipes are not the Swiss army knife of the personal hygiene world. Quite on the contrary, if you use nothing but wet wipes, please tell me so I will keep my gloves on next time we meet. No, wait. Make that a hazmat suit, you scruffy bastards!