This is quite an extreme take.
Splitting a 100 euro meal is not the same as a 2k AirBnb. The OP didn't say they just booked a place and forced people to go. I'm assuming that a family going on a big holiday agreed to do so together and had some input in the size/no. of bedrooms etc.
I would try and read the original post first next time instead of throwing out words like callous and accusing people of taking advantage of their family.