People like this believe their opinion matters in a sea of billions and billions of contradicting opinions where only a few control the tide. No one important cares what you think.
Abstaining from voicing an opinion is only wrong in case someone else needs your opinion to make an informed decision, and you suspect they might err unless your opinion is made clear. Otherwise people are not privy to your opinion.
And "your politics" is almost never needed by anyone else (same goes for "my politics", in case someone thinks I'm being condescending).
You should have noticed that all people who demand you to speak out never give a rat's fuck about what you really believe in, and will denounce you as "privileged" as soon as you step out of the party line. Your political opinion only matters as long as it coincide with theirs. To these people, you are a parrot, a loudspeaker, not a person.
On a daily basis, people have to interact with people whose opinions differ from their own. If we go around forcing our opinions on to everyone else 24/7, we’re liable to lose friends and family, even jobs. If a person is in a position where none of this is a problem, they are the privileged one.
Actually, I’ll go ahead and say that anyone who posts “self-care is important” is probably privileged anyway.