Q: Why are there jerks and assholes?

Because they know that to be otherwise is to get stepped on -- to be used and disposed of.

We like to think that if we gave our hearts out and worked hard for people, gave away our extra time to finish a job or furnish the details, we'd get rewarded for it. Slaving away behind the scenes in the vain hope that we'll be appreciated. That's what happens in fiction.. the good always get rewarded in some way, shape or form.

The reality is that there are a lot more selfish than selfless people than we'd like to think this world breeds.

Yes, doing good deeds can make you feel good on the inside but it can be hard to consistently find that inherent and intangible reward in the good act itself.. especially if it flies under the radar too many times. In this day and age not a lot of people care about anyone other than themselves, or whoever's pants they're trying to get into or whoever can help them up the social ladder.

Maybe some people choose to be a dickhead because they'd rather work and help themselves -- where they'll definitely feel the benefit through self-reward -- than work for others who will probably acknowledge and/or appreciate them.. or probably not.