The point I don't understand is how anyone could consider...

The point I don't understand is how anyone could consider capital raising beneficial to shareholders.

Take this line from the BusinessDesk article about the 3rd largest shareholder (who own about 3.5%):

"A spokesperson for Synlait shareholder the Accident Compensation Corporation told BusinessDesk on June 7 it would consider any board proposals, including capital raising, aimed at protecting shareholder value in Synlait."

Capital raising will not protect shareholder value, it'll do the opposite. The only route to protect shareholder value is to force the major shareholders to take over the company. Rejecting the loan will accomplish that, in my opinion. They won't end up with nothing, and they may even end up with a bidding war for their shares. Better than nothing as they say.