This question can only be answered by the musing.
If musing is powering down, then they have their own personal reason for that. And also if they decide to sell steem at this current steem price, they also have their own reason for that so nobody can know why they are powering down as the question can only be answered by them only.
All you just need to do is don't worry about whether the musing are powering down or no, continue blogging and continue asking the question you feel bothered your mind and also continue providing quality answers to questions also. Musing owns their sp so they can decide what they really what to do with it.
I asked the same question 40 days ago (on 2018.12.01), and I have received some good answers to the question: https://musing.io/q/xplosive/pkcdsfxkw.
While you don't have to be bothered about the powering down of @Musing, we have to understand that resources are invest in @musing project. The investors reserve the rights to withdraw their dividends.
We are only favoured to enjoy the curation we have not laboured for in @Musing. The Musing.io team is superb!
There are some operational costs on musing which needs to be managed,some of the operational costs include giving an incentive to the musing curators...
i got an information that the liquid steem gotten from the power down are used to pay the musing curators....i don't how confirmed that information is but i think it is true.....
Probably paying their costs.
All apps have operation costs, such as:
Servers, electricity, tax, in case you're employing someone, you need to pay them.
Musing makes a good buck thanks to the 1,000,000 delegation they received.
It is only natural that some of the earning would be redirected.
An app cannot operate indefinitely if you simply reinvest 100% income.
When Musing powers down, it doesn't have any major direct negative effect on Musing or its users, so, not to worry.
The reason Musing is powering down is because they want to pay off their workers (Probably their curators and other people in the technical department) and that of course doesn't have an adverse effect on their delegated SP as they can't power down that one.
Every app has operation costs. And some really big. That could be a reason. There are dapps that pay their mods or admins with liquid steem instead of upvotes on determined scheduled comments.
But I wouldn't be surprised even if they decided to have some liquid steem for trading...prices won't be there forever and with a smart trade you may double or triple your holdings