They want to build him for this reason: Huntsman is not a religious candidate. His views on climate change and evolution and gay rights make him someone that the media wants to root for.
Gary Johnson:
Believes in evolution
Believes in climate change
Is gay-friendly
Was a 2-term governor
Why won't the media cover him (he's living off scraps right now while Huntsman is wasting his large amount of coverage)?
Johnson also advocates for legalizing marijuana.
I think the mainstream media writes him off as a result.