It's a business, not a charity.
You said it yourself. If I was head of Paramount, I wouldn't green light a Trek film with a $185m budget, knowing it's probably going to only make somewhere between $350-$400m worldwide, when I could spend $200m on the next Transformers movie knowing that at the very least it will gross $900m.
From a financial perspective, Star Trek 2009, while certainly not a disaster, was far from the best use of $150m. Into Darkness will be the same.