Yes, all whistleblowers should be treated as heroes, if only to encourage the behavior of whistleblowing. However, this is not the only reason. Whistleblowers provide a much needed service to society; transparency. When a whistleblower blows the whistle, s/he exposes corruption, and this is always a good thing for society to have.
Whistleblowers should be treated as heroes if they are not endangering the lives of innocents by divulging information that could possibly bring harm by exposing secret plans or other such classified information. If they are only exposing corruption and are not causing harm to anyone undeserving of it, then they should be treated as heroes.