I am interested in Salesforce because
- there are a lot of jobs for Salesforce.
- it is not a generic language, it is used in a specific field, so you are specializing. Specialization makes learning interesting.
- since it is not a generic language, it might take shorter time to master.
- it is related to marketing, which could make the work more interesting.
On the other hand, I am also interested in C#, but it is only a generic language.
Since it is generic, it's less interesting and you might take ages to master.
These are only my personal opinions, I might be wrong.
One would arguably never "master" C# entirely. It takes probably 2-3 years of job experience before one becomes proficient in it, and it's always changing so that the skills must be kept up with.
I'm not seeing all these Salesforce jobs out there, but that might be different in different parts of the country.
I think that the generic languages, as it were, are more interesting, because there's no end to what you can do with them, but that's different for everybody, a matter of taste. So, for instance, I'm not interested in marketing. Even if marketing is interesting, the types of work you'd be doing in Salesforce would not necessarily be as interesting (would probably be lots of repetitive tasks like setting up different forms and views of the data).