No one ever says a project has to be, at all. They just frown and look disappointed when you say no.

Very same reaction if you have a side project and want to protect the IP you're doing outside company hours to work on that same side project. All the contracts I have signed had that unfair but standard clause that say all the IP you are producing outside company hours belong to company

I have always been able to get that clause stricken from a contract. It's totally unreasonable.

How is that legal?

In other words, your side project is just more, unpaid work?

It's worse than unpaid work, it's taking ownership of your personal hobbies. Presumably your side projects aren't for your work but for yourself. Imagine if a chef had to pay his employer for the meals he makes at home. Makes no sense.

More reasonable would be an industry non-compete or technology NDA which are more specifically about you not taking company secrets and making money from the company's efforts.

Granted I’ve only worked for small, software-focused companies, but the companies I’ve worked for have had pretty reasonable contracts saying that anything I create outside of work hours without using work equipment or work secrets is mine and not theirs.

You don't have to be "productive" with every minute of your life.

GP's just rebranding 'having a hobby', didn't say anything about being productive 'every minute of your life', or even that it had to be productive at all.