Can anyone explain me this phenom? Is there an anthropologic reason for this behaviour?
A man builds. A parasite asks 'Where is my share?'
A man creates. A parasite says, 'What will the neighbors think?'
A man invents. A parasite says, 'Watch out, or you might tread on the toes of God... '
Perceptions chance over time, including those concerning yourself. Some actions can be justified in different lights under certain circumstances, which can lead to people doubting their justifications for acting as they do in other situations as well, it's like a domino effect.
The fact that so many people are changing at once may be a result of said individuals feeling it's more socially acceptable, then looking into any doubts they have and magnifying them, like a mob mentality. Or, it may be coincidence. I wouldn't doubt either.