Imagine you leak some important classified information to Wikileaks and they don't publish it. You'll just send it somewhere else. There are hundreds of journals and thousands of journalists to whom you can alternatively send the information. It's frankly speaking stupid to claim that not publishing a leak "for strategic reasons" could somehow be harmful. It is also worth mentioning that journalists do that very often for a vast number of reasons such as national security, their own security, protecting contacts, protecting sources, fear of legal repercussions, political agenda of the editor in chief, etc. There is nothing special about Wikileaks in that regards.
What was special about Wikileaks was their policy of publishing everything with only minor redaction and, most importantly, without asking the befriended intelligence community for the green light first. That's what normal news outlets tend to do, unless they have a very high level story like Watergate.