Earlier quoted context omitted.
There was nothing arbitrary about that choice. This bank promised better deals BECAUSE they were not careful enough about the risk it entailed. That was their competitive advantage, and they made bank for it. Well, tough luck, now it's not anymore: it has nothing to do with being a large bank or a small bank, it has to do with healthy business practices.
Many startups chose SVB because they were the ones willing to open a bank account for them at all. I remember going to a branch of Bank of America to open a bank account for Posterous and not being able to.
(understanding it may have had little to do with why they tanked)