The only answer I can come up with is that there are unemployed folks who wish they had your job, so that's why it's considered taboo to say you are indifferent or hate your job. Some people have legit reasons for being indifferent or hating their job: Coworkers, management, etc. Even then, go to work, do your job & go home. The dislike comes from some people kiking with their colleagues, and the moment a colleague gets a raise or promotion, shade is thrown. The shade can become so toxic that it's felt in the atmosphere. In the social media age, colleagues have gotten fired for airing their grievances on social media; that's another reason it's taboo to admit hate or indifference for your job. If I didn't like my job (which is false, because I enjoy my job & look forward to advancing in the company), I wouldn't put it on social media because of rats. It's wild...that's all I can say.
