Because SVB lacks the liquidity to pay out the bank run but doesn't lack the assets, at least as long as you only pay out deposits (which is what they are doing i.e. "Shareholders and certain unsecured debtholders will not be protected.").
The thing is that without this decision there would be two problems:
1. deposits would only re-accessable much later, too late for most small Companies to survive
2. depending on law/regulation aspects I don't know much about it also may have been a possibility that Stockholder get payed out first and similar
The thing is that without this decision there would be two problems:
1. deposits would only re-accessable much later, too late for most small Companies to survive
2. depending on law/regulation aspects I don't know much about it also may have been a possibility that Stockholder get payed out first and similar