While I agree that using youths to put the message across is somewhat exploitative, at the same time, does anyone think little Greta has changed any minds and convinced any adults?
Not really.
Greta is there to rally the youngsters around a banner of "You're destroying OUR (meaning the youngsters') planet and stealing our future".
Aiming at that audience reinforces the Leftist education system's mantras of Anthropogenic Climate Change and the draconian totalitarian remedies being sold, in desperation to the target group of children and teens.
Adults see this 14 year old child as a wonderful poster child if they are marching in lockstep, and a bratty nuisance if they disagree.
This is an example of fighting fire with fire, but this young lady, Naomi, at 19, is someone old enough to form an opinion, who would be old enough to vote here, who can present a different viewpoint to that same target audience of children and teens without the automatic rejection of elders so common to the age group.