The reason why they do this is because you could pretend your are working for them but actually do something else on the side during the time they are paying you. The only way to avoid is is by completely banning other work. It really makes sense from their side
You could, and then you either are still able to deliver an amount of work that makes them happy, in which case, why do they care - or you can't deliver an acceptable amount of work and they can fire you for performance. No need to own 100% of anyone's time.
This makes zero sense, and sounds more corporate slave-ownership.
If you are going to pay the going hourly rate for 168 hours a week, yeah maybe there's something.
But if you only pay for 40 hours a week, that's what you get: not a single minute outside of that. And especially not something the person did or invented at home.
> I get the impression most people don't read their contract.
We read them, one of two situations occurs:
1. We don't care and sign it.
2. We raise a stink about it and either they change it or we don't take the job.
My current employer had the clause because it was standard boilerplate contract, but when I expressed my concerns over it and told them I wouldn't sign with it, they amended the contract to make sure nothing in it would impede my own projects and company.
Now on my 1-on-1 my CEO often asks me how my side business is doing and gives me advice as needed about building a business.
Did you not read what I wrote? I said you could work during company time and that is why they do it. It's not just that. You can realistically only work a few hours a day properly so if you spend all your thinking power on hobbies there is little left for the guy who pays you