Term for the opposite of a scapegoat

I feel like poster boy (or, the gender-neutral term poster child) is a better choice than martyr to describe this.

According to Wikipedia:

Metaphorically, "poster child" is used for a person of any age whose attributes or behaviour are emblematic of a known cause, movement, circumstance or ideal. Under this usage, the person in question is labeled as an embodiment or archetype. This signifies that the very identity of the subject is synonymous with the associated ideal; or otherwise representative of its most favorable or least favorable aspects.

The meaning is slightly different in that in the most traditional sense of the word "poster child" the real human identity of the person is lost in favor of the idea of what they're suffering from, and it sounds like your concern is too much focus on that individual and not enough on the larger issues at hand.

You could perhaps coin, "poster victim" to highlight the idea that these sorts of articles focus exclusively on the individual's victimhood?

Would you consider the ironic use of the idiom to make a martyr of?

I found the following contextual quote in OED for example: He who perishes in needless dangers, is the Devil's Martyr.

If you are adamant about a single word expression I recommend objectified. Objectification is defined in OED as

The demotion or degrading of a person or class of people to the status of a mere object as in sexual objectification of women by the mass media.