> Most ideas are trivial, or very hard to protect, even while building a business.
Exactly, because they are worthless.
The exact details of how SpaceX achieves re-usability are very much patentable. The idea that initially was on Mr. Musk head isn't and wasn't.
> But what about patentable ideas ?
They do not exist. In order to patent something, you have to be able to describe your "invention". Which means you have executed it to some extent, insofar as you are able to at least produce a design. But the mere fact that you can patent an idea doesn't make it useful. The patent office abounds with patents which never amounted to anything.
> What about fully formed ideas coming from professors, backed by deep research
These are no longer ideas, are they? Someone had an idea, pursued it, with _the help of a team_ and produced something of value. THAT can be stolen. The initial idea that spurred the research cannot.
> What about an idea(deeply researched) that with relatively easy implementation could get a lot of press, high SEO and some defensibility
Then you don't need that much funding, do you? If it is easy to implement, you go ahead and implement it, and _NOW_ it has some value, if your implementation is any good. Still, you need to produce something for it to have value.
> They are advantageously positioned to be able to fund a team to execute an idea, theirs or otherwise.
So they could unethically become a competitor. Big deal.If the idea is not originally theirs and they do not have the founder on board, then they will end up building something different. For better or worse.
They can be at most a multiplier. But what really matters is the execution.
For instance, "Rockets should be reusable" is an "idea" that even kids can have. Achieving that is the interesting part. Many tried.