Coming in at a late point in the conversation, though I don't think both sides of the argument has agreed on anything.
The common ground here is that beating up and killing children is horrible. In game, when coming into an area to do your bounty-hunter things (pretty much the common reason why you'd be traveling at night in Port's Ouvriers), a PC's faced against the same moral issue. There are many ways to see it, but here's a couple:
Seeing as adventurers comes at night to kill their fellow neighbors hunted by the Council, people have no choice but to be suspicious about travelers at night, since they'd most probably be there to kill you. This could be compared to the Barovian ways of categorizing adventurers as "outlanders", except that in this case we are to crazy ones we're calling them.
[A waif arrives in his home, bringing the plates and jewels left on a recently killed cleric, or only what wasn't already looted] "Hey dad! Look what I've got! Those jewels must be worth enough solars for two days food for mom and-" [the father turns his head with a stern expression, motioning the kid to give him the jewel. Hopeful, the waif goes to give what he found to hia father, before getting smacked on the cheek] "That's really all ya could've gotten you useless piece of-"
And I'll stop there. But from my point of view, that would be what everyday looks like for those kids. Hopefully the father won't spend all the gold on booze though. The point I'm trying to make, as some others have tried before, is that to the people in Port's community are left with an unfair way of living. That you give them gold and pity during the day, they'd probably think you're a fool wasting money, or that you have stuff worth stealing.
Waifs represent a stage of life the bandits has to go through before having a bounty on their head. Bounty the noble crew chose for them to have by making them live in poverty, because that is the price for their luxury.
So I'll asking you something for them: "Why the hell are you in my Quartier in the middle of the night?" The answer would most probably be: "To kill your neighbor, for those with the gold offers a reward on his/her head." Would we be doing a waif favor in not killign them, or are just waiting for their heads to grow into a more juicy reward?
So to answer, I find the children's reaction rather appropriate. This whole thing? Truly... Dement