Most Americans get two weeks off a year, if they're lucky. There's no way to make this "outside your day job."

It was designed so that wealthy landowners could attend sessions more easily. Just like the u.s. senate does not represent the population, but the land area. The writers of the national and state constitutions were almost all wealthy landowners.

In my opinion, given the size of the population and the complexity of the economy, full time politicians who are paid very well combined with draconian anti-graft laws are needed.

Did you mean after your slaves plantar and harvest?

The difference is that in ye olden days there was simply much less need for full time legislators. In an era where 90% of the population lived on largely self-sufficient family farms, and large scale economic regulation wasn't widespread, part time legislators made a lot more sense.