Why don't journalists simply quote Obama's original stance on whistle blowers, and ask him to respond?

Because real journalism is dead in the US mainstream media.

Real journalism is hard, it requires not taking sides, research, asking tough relevant questions, and filtering out the bullshit and propaganda, then finding the truth and communicating it to the public in an accessible way. All of which requires motivation, intelligence, a belief in the public good, credibility, a desire to speak truth to power and hold the powerful accountable. None of which applies to the vast majority of mainstream outlets today.

Corporate media wants the absolute minimum cost to generate content in the shortest possible time that maximises ratings (i.e. creates drama) but without upsetting other corporations, lobbyists, and advertisers. Also, given that most of the media is owned by half a dozen conglomerates, the media companies cannot risk or upset the other subsiduaries or call into question the close relationship between corporations and politicians.

Investigative journalism is the antithesis of the above; it's expensive, takes effort, takes time, requires an unbiased attitude, and risks pissing off the powerful - it's much easier to skim the surface, regurgitate press releases, oversimplify stories (i.e. good vs evil), make up stories or deliberately misrepresent the facts, and to lob softball questions at the powerful. After all, if you ask tough questions then they think politicians will stop giving access. Then with that environment, the effect on the journalists is pretty much a done deal.