Clearly, Ethereum is a security. There was a massive premine by the founders to pay themselves, there is an organization that runs it, there is an advertising budget, employees, the entire blockchain of ETH can be manipulated by the foundation, such as after the DAO attack where the chain was rolled back by the organization. It is also a very slippery slope seeing ETH having an ETF as it is a proof of stake token. Control of the network will inevitably centralize and this gives more and more power to the same people over time, because only the largest holders are the ones rewarded with new coins. Then there is the issue of the thousands of 100% pump and dump scam coins running on Ethereum. Should people be able to gamble on scam coins? Probably, but for the SEC's job to be stated as protecting investors I don't see how that can possibly work for it to be endorsed.