The dairy industry and the egg industry are dominated by people who don't do the ethical thing, and treat the animals extremely badly. There are a smaller number of companies who are trying to do the right thing, and have free range chickens or cows that are treated well or whatever.
So, if a smallish number of people - and vegans are a definite minority - decide they are going to avoid eggs and dairy altogether, they are taking away the market for the free range eggs and such. It's not going to be the big companies that treat animals badly that suffer, says my brother. It will be the smaller, ethical producers. And in slightly lowering the demand for that product, all I do is make the companies want to cut costs. And who can cut costs? The crueller types, by shoving more animals into smaller cages and doing all those reprehensible things that such people do.
Therefore, by becoming vegan you contribute to animals being worse off. So says my brother.
I no longer know what to think.