My question is: would you consider legitimate markets for buying and selling hash power to be a scam? If so, why?
Considering there is absolutely no way to get any kind of return on your investment I'd say it is most definitely a scam.
Thank you for answering.
I disagree of course. Entities
selling hash power would earn slightly more on average than pointing their equipment at a pool (so sellers
do have an ROI advantage). This bonus is paid for by entities
buying hash power as a way to express their vote. In other words, what we're seeing is a market emerge for the ability to construct blocks according to one's volition.
Constructing blocks according to one's volition has value; it's how Bitcoin's consensus mechanism works and evolves.

Of course I'm referring to the buyer's ROI.
The nonsense you just typed has nothing to do with the reason for the existence of cloud mining
services ponzis. Literally no one but XT retards are buying cloud mining to "construct blocks according to one's volition".
The simple pretense that these shenanigans would somehow move the needle in the balance of power is asinine and for you to defend such a scheme shows how desperate you and your gang are.
There is no "vote" Peter and what you describe has nothing to do with Bitcoin's consensus mechanism.