Is this not the point of a deliberative legislative body?
But in practice, a legislative body may or may not deliberate. And that deliberation may or may not include reasons for some of the parts of the legislation. (And it virtually never includes deliberation on a small clause like this.)
But at the end of the day, nothing has to be deliberated on. It's just a majority vote at the end of the day.
Many of these small clause discussions go on around amendments.
There is less deliberation on policies (rules) and regulations (how an agency decides to implement a passed law). There is deliberation of course but it is more opaque to the public and less record is made.
Whether it’s easy to do effectively by the public is another thing.