They're right, it isn't legal. The only legal way to acquire a usable ROM in the US is to rip it yourself from a disc/cartridge that you own.
That doesn't mean that it's wrong to download ROMs. I've done it. It's just not legal. People are confusing a factual accounting of the law with personal moral condemnation.
That doesn't mean that it's wrong to download ROMs. I've done it. It's just not legal. People are confusing a factual accounting of the law with personal moral condemnation.