One doesn’t need to work at a startup for most of this points. My company is over 16 years old and we also meet the following bullets:

  * Less bureaucracy, more building
  * Larger impact on a product; not just being a cog
  * Generalist rather than one narrowly defined job
  * Ability to learn many new skills
  * Working on something they believe in
  * Working with newer technologies
  * Flexibility (work from home, set own hours, etc)

Most of our engineering team has stayed for more than 5 years. Some have been there for 15 years.