Nobody really calls themselves an "idea person" unless they actually have no real-world entrepreneurial experience to bring the table. It's like wrapping yourself in a giant red flag that says "I'M A USELESS LEECH".

  Did Mark Zuckerberg not conceive of the idea of Facebook? 

There was no "idea person" behind Facebook or Twitter. They were founded by the engineers who came up with the idea and built the product. Nearly all successful technology companies are founded by engineers.