Why does a person that choose to be single with no dependent gets penalized?

[theking]

So a co-worker told me that when ever his family do a share family event such as reunion, his brother and two sisters always asked him to cover more of the cost just because he's single with no kids. He feels that since they have the same financial resources, they should divide the cost up equally especially considering his siblings have kids and they as a whole utilized and consumed way more of the stuff during those joint events such as food, space, and activities.

I told him that what he said makes sense and that he needs to explain it to his siblings the next time they plan to do a joint family event. I also told him that just because he chooses to be single with no dependent, he shouldn't get penalize for it.

Any of you run into similar scenarios? Thoughts?