1. The universe is so fucking large its impossible there is no other life.
2. Aliens is just a word. Life from out there could be human like or also just a little bacteria (already said)
3. Why the fuck everybody believes alien wouldnt attack us or even help us? Its just...well...native? When the aliens have a higher technolgy doesnt mean they wouldnt attack us.
4. Seriously, not everybody on earth would be happy.