Are you suggesting that Bitcoin's security hinges on peoples good faith (not to deploy "hundreds of nodes with multiple amazon Ec2 instances without users actively securing them and using them"?!
I said the exact opposite.... but to answer your insinuation: the answer is in understanding the fundementals of bitcoin -
Full nodes check for the --- The
longest valid PoW chain, so a "51% attack" would need to be carried out along side a Sybil attack.
If a majority of the economic majority or nodes broke away from the majority of the hash power than they better quickly switch PoW algo's as they would indeed be susceptible to a 51% attack.
Here is an example of a backup plan devs have if miners ever go rogue or do something stupid-
https://np.reddit.com/r/Bitcoin/comments/41aocn/httpsbitcoinorgenbitcoincorecapacityincreases_why/cz0z9ymhttps://github.com/luke-jr/bitcoin/commit/8d3a84c242598ef3cdc733e99dddebfecdad84a6Keccak with a Nf15 appears extremely ASIC resistant.
***Clarification*** This is just an prepared idea and not a plan. The core devs obviously are prepared for the worst case scenarios like miners being compromised or doing something idiotic like raising the 21 million limit. Luckily most mining pools are intelligent and have our best interests in mind like most of the developers and these drastic steps likely will never be needed.