The idea of having two houses of parliament is common in most large countries, and it is also common for those houses to be segregated from the executive (EU etc...).
The US is a political and cultural mess, but a lot of those issues aren't inherently due to the political system involved.
Neither of these are exactly unusual or extreme positions w.r.t systems of government.
Or is this just a whine about the U.S.?
The parent comment just gave reasons for that (among other things).
Republic and democracy are orthogonal concepts. A republic is a form of government where the head of state is elected. So it is in conflict with a monarchy, where the head of state is passed by inheritance. In democracies decisions are made by the people through various means, like elections. In fact many (most?) republics are democracies, where the head of state is elected by the people. The US is one of them, the "the original" one Athens was as well.
However there are republics where the head of state is e.g. elected by a clique of oligarchs or the military. They are undemocratic republics.
When you patch one aspect it throws the other aspects out of whack.
I'm curious- do you have something particular in mind?