I don't get it. Why would you want to remove the opportunity for overtime from any professional? Obviously the employer has a (potentially huge) finanial incentive. But what's the government's view here?
People paid for their labor are paid by the hour and get overtime. People paid for their thoughts usually get paid per year, and don't get overtime.
I guess the general idea is that you are always thinking, so how would it be possible to decide when you are or are not on the clock?
(Obviously this is a generalization with lots of exceptions, it's just so you have at least an idea of the reasoning (since you asked).)
Also that whole "related to their business" is over-reach as well. If I work for (say) a database company and am providing quality work but spend my nights at home designing a new kind of database, what possible (reasonable) claim can the employer have on my private work? All this and yet we are "employed at will".
Yah, and in fact that is exactly what they do. Usually they make you give them a list of any prior inventions you already have, and they claim ownership of everything else.
Obviously you can negotiate and not sign it, but it's pretty typical clause.
I can see why government would legislate to protect minimum or baseline employment rights, but why remove the possibility of earning overtime from a particular group of people? Is this law just about ensuring equivalent practices across all states, or was it simply bought by employers to reduce their costs?