It's not the bankers placing the pump-and-dump scam ads all over the internet.
The general public should be scared of investing in coins. It's a very high risk sector backed by optimism and not much else.
Much of the code is open source, and the key ideas were created by university researchers before bitcoin existed and they are not patented. Amazon, Google, Microsoft can choose to add blockchain and/or coin services to their cloud offerings at any time. So can nations and corporations.
I don't disagree.
However, something that is repeated countless times is the idea that the big players will just come up with their own anyway, and those are guaranteed to be the ones that last the long haul.
Has no one paid attention to the history of startups? They topple or beat the stalwarts time and time again. Something to consider is often the big players are slow to move, due to the weight of their corporate bureaucracy. Of course, you also cannot write off the giants, because if they don't beat 'em, they may buy 'em. But then that gets trickier in this landscape, because most of these projects aren't corporate entities, nor do they intend to be; they are distributed, open-source, written specifically to eschew centralization and how that could impact the foundation of the currency. They want it to be outside of truly centralized governance. Generally, at least... there are more centralized projects or even distributed open source projects that through a core development team otherwise projects governance all the same. This is of course the nature of open source projects with an otherwise stable lead development team. But quality non-profit organizations can steward projects often better than a loose community.
I digress. My point is that these major players may very well swallow up the core development teams, or do so with a very strong indirect influence via contributions to an otherwise independent non-profit organization. Again, look to the Linux community as a chief example: core kernel development is essentially independent, but there are code and monetary contributions from major enterprises and there is a natural steering of the project's future by said enterprises, and these enterprise outfits otherwise operate based off that code and stay attached to that upstream code and yet do so independently, developing their own project that utilizes that open source code.
Crypto currencies will remain decentralized, but I'd bet that the titans of tech today will not own or control the most successful code bases, though they may have a seat in a steering committee or otherwise influence the project. But I'm thinking projects like NEM, Ethereum, etc, the truly versatile projects, will end up serving as the common core between disparate privatized solutions. Even if the activity isn't directly involved in, say, Ethereum and its dApps and private chains that produce activity on the public blockchain, the public blockchain still records encrypted data on blocks that continue to grow the chain. For sure I expect some major company to bring its own project from scratch, and perhaps it'll gain traction, and perhaps it could become the dominant project of them all, but it's just as likely to not be one of them.