Why people work at certain companies when the money is not the issue

Start from this - Pay people enough, only to take the issue of the money from the table. Then go with meaningfull things (start treating people as people:-) and you will see that the money is not the issue.
And the most important things that motivate are:

• Autonomy - self direction.
• Mastery - we want to be better at stuff.
• PURPOSE motive!

Dan Pink: