Well, we believe that buyers should be able to get hashing power for an affordable price and this is something our marketplace offers. This could however virtually look like less earnings for miners, but if you take dev fees, pool fees, wallet fees, exchange site fees, ... in calculation, it is always better to mine with NiceHash.
Of course you can always risk your extra time and deal with pool/algorithm/altcoin switching/exchanging and paying fees along the way and I'm sure there are better options than manually switching, but many people rather enjoy basically hassle-free-autopilot mining with NiceHash.
The only people profiting from your exchanges are auto-bots. Hell they even resell your hash on Miningrigrentals and pocket the difference.
Equihash has stuck pretty close to the coins they hash... other algos are not nearly as lucky. Take Neoscrypt for instance that earns close to 30% less then Feathercoin. Lbry algo is earning about 50% less then Librarycoin. There is a reason miners prefer mining coins direct and it's not just to get the coins.
Most good pools are about 2%, dev fee is usually around 2%. Depending on when you sell your coins you can easily make up for that difference.
You could do a auto-exchange multi-pool, something like YAAMP or YIIMP, charge a 3-4% fee for mining that way (depending on the coin) and then allow people to purchase hashing power for MORE then it costs to mine the coins direct. That way if there isn't a coin that people know about, is unpopular, or just someone wants specifically coins, they can still get what they want and miners aren't constantly being pushed down by auto-bots that control your marketplace.
It's more complicated, but not only does it raise the value of coins (forcing people to exchange for more then they're worth), it also allows miners to stay in business and use your service.
The only people who don't win are those that are currently running the auto-bots on your marketplace right now. Nicehash would still get paid, miners get paid, and you're supporting the coins you mine by forcing a net positive injection of BTC into whatever is being mined. This is essentially what Miningrigrentals currently does (miners almost always have their prices set higher then common coins people mine). MRR is just much more organic. Hell you could even roll MRR services into your platform and raise the prices based on it (what the 'new' fixed rentals would amount to OR allow people to show their rigs and rent them direct).
Nicehash doesn't need to push prices down to earn money.