It's not about changing advertising business model.
It's more about feeling better.. and telling our own truth (it's hard to be fat, black, mutilated, trans..) should not be censured because "body positivity attitude"
Nothing has changed in how most people feel about themselves; instead, it’s simply become very gauche to articulate any of those negative feelings. That wouldn’t be very body-positive of you.
But I'm biased against any "positive" thinking since that :
Even more biased against Negative thinking. But the opposite of Negative self-talk, it's not positive: it's objective/realistic thinking.