The coins we switch to that have low difficulty are in fact more profitable. Even with the high reject rate, sometimes as much as 70%.
The people who benefit from these coins most are those with low reject rates. Not those with high hashrates.
High hash rates and luck lead to lower rejects, while ping also plays a smaller factor. The smaller miners (5xxx and 6xxx cards) get crushed with these coins, while fast cards don't fare all that much better with 512 difficulty coins.
If I'm misunderstanding something, I apologize. I'd appreciate an explanation to understand properly, though.