That's right.
Posting something on my timeline is like using my voice.
When someone asks me to post, they are asking to lend my voice.
If they ask to post what I would generally post, that's fine. I am just using my voice.
When I lend my voice to irrelevant parties, I become that irrelevant party.
No one wants to remain subscribed to an irrelevant party.
I lose my reputation here at the cost of that irrelevant party getting more eyeballs. They win. I lose.