These deals aren't as slimy as they look. Yes, there's no marginal cost, but the goal is to spread out the costs as evenly as possible with the companies using the software. Setting the price per core just means that the companies that might do more processing shoulder more of the software cost. (And, yes, it's another way to gouge companies. But it's gouging based on use.)

Not necessarily slimy. The problem is that there is no clear right pricing where there is no marginal cost - makes it hard to decide whether the pricing if fair or not.