It would depend on how obtrusive the ads are going to be.
If the ads are distracting and if they affect the way I use Musing.io negatively, for example, if I am forced to view ads before answering or posting a question, or if video ads start automatically playing upon loading a page, then I might be compelled to stop using Musing.io.
However, if the ads are simply display ads that are placed on sidebars or in between questions, then I will still stay on because these are just everyday realities in the Internet nowadays. I am used to them enough that I can tolerate them.
Hopefully, though, Musing.io do not start showing ads. One of the things I like here over Quora is the fact that there are no ads weaved within the content.