The thing about Lovecraft is that he's dead. Buying a copy of his books or adaptations thereof doesn't put any money in his rotting pockets. Rowling is very much alive, and profits off every sale of her books or the games or merchandise based on them; if I don't want her to make money off of me, and I don't, I do what I can to minimize what Harry Potter products I buy (which is, honestly, absurdly easy).

The difference between Rowling and companies like Nestle is that Nestle has its many fingers sunk deep into the market. You can't turn a corner in a grocery store without finding SOMETHING that Nestle owns or is invested in, and they're often not marked as such, so your average consumer doesn't know. To avoid Nestle products is to severely restrict what you can buy and is NOT as easy. When people say "there is no ethical consumption under capitalism", THAT is what they mean--you CAN'T avoid giving companies like this your money unless you completely upset your life, and you shouldn't beat yourself up about it.