Because those are hot button topics that people easily get riled up about and provide excellent distraction from the humdrum but really important stuff.
Yes precisely - its the economy and how massively over-manipulated it is due to lobbying. All those things you named fall out from the economic policies - or rather bazillions of exceptions and special-cases - that corps get in return for their dollars. Dollars that are pretty evenly split between both parties.Really the only thing that effects the majority's day-to-day life are economical issues. Do we have jobs? Are gas and food prices going up? Can I afford a house? How much taxes do we pay?