Yes, they own it, in exchange for protecting you from the 90% chance of failure (perhaps you should save your best ideas for when you've acquired enough resources to build it on your own? I don't, ideas are cheap, it's the executions on those ideas that has built value for me).

And I don't think startups are reckless, but I think a lot of the people that join them fail to do rudimentary financial calculations as to whether doing so has a better expected return than a safe(tm) job.

Otherwise, they wouldn't accept chicken scratchings worth of lottery tickets and 20-50% lower compensation. But yet they do, over and over, no matter how many people lay it out how bad an idea this usually is.

https://michaelochurch.wordpress.com/2012/07/08/dont-waste-y...

How noble of those large corporations to save you from yourself!

So, basically, your point is that you should sneakily hide your best ideas from your employers and then strike out on your own when you hit that magical amazing idea! You know, that idea that is obviously going to be an amazing success and you can know that ahead of time! People that foolishly try to succeed on their own time are rubes! Instead of accepting a check from the government, you should mail it in with a job you're entirely checked out of until you find the magical secret sauce to make yourself a billionaire. That's great for everyone right?