Why is political polarization a bad thing?

Government works best when parties find common ground and seek compromise. That is the business of governing. Polarization widens the gap between parties and results in a standoff, accomplishing little to nothing in the way of governing. Tyranny is the result of total dominance not by a party but by the concentration of power into an individual office or official, or into the hands of a small ruling group, i.e. an oligarchy.

Slowing the government down leaves the needs of society unaddressed, unmet. [i]That[/i] is not a good thing.

Indeed