Isn't it more about "showing personality" though? People who post about stuff from their perspective, from their understanding, that's the essence of their thinking. I guess one could call it a brand. But some people have actual brands where they cater for an audience, in a way their audience likes it, some are more successful, some, like mister boom said, are on level of post about turmeric benefits.
Oi, oi! You start to sound like Yoda there :P
I think people should feel free to like something because they like it rather than feeling of some sort of obligation to care etc.
Yes - people often hide themselves and their uniqueness to be like everyone else, when it is what makes them valuable. It is like daytime soaps where all the women have been to the same surgeon and ordered the same lips, nose and chins.