The value droped hard since december.
https://www.coingecko.com/de/kurs_chart/steem-dollars/usd

But even if it wouldn't have: Just because some people buy SBD that doesn't mean that a content creator here on steemit gains additional SBD. He only would get additional SBD if someone who bought SBD would transfer it to his steemit, convert it to steempower and upvote the content creator (effectively tipping him with his own money).
But this kind of generosity isn't seen often in the internet.