At this point I am not 100% certain what the exact answer is for this question. I think there are some people who have passion out of the gate and no monetary strategy, and I think there are some people who have a monetary motivation and no passion for their topic. I would even go as far to say as some of the extremes in both of the examples mentioned have no expertise when they start blogging, but that doesn't seem to stop them.
On the other hand there are people who have plenty of experience that can simply benefit other people.....
Even though these people have experience they fail to get started. Myself included, and I think it's because they feel like an imposter, or they feel the need to have it all figured out. So I'm taking the position that it's you should find the strongest combination of things the rely on your abilities, peoples needs, what they are willing to pay for, and what you are most passionate about. I think passion is a requirement to reach certain levels, but passion alone is really just that; it's inspiring, it's intriguing when it comes to running a business; when it comes to blogging in a manner that could lead to something where it could provide an exchange of value both to the writer and to the reader however, passion alone is not enough.
So what happens if you don't know what your passion is or you don't know your expertise?
I think the key is to play two games simultaneously. One game is the long game, and the other is the short game. Only you can decide what factors, or variables you have stacked in your favor, or against you, and figure out what you need to do from there.
Some people will need to do one thing and focus on one thing until they become good which I think is the majority of people. Some people have clear talents and money and need to figure out their passions. They just need to try lots of things quickly and without loyalty. it doesn't mean without integrity , it just means you don't have to dedicate 20 years to something you're not passionate about. You do need to have integrity on the other end however, and give yourself time to learn a craft, if you need to acquire expertise about something or if you are trying to monetize that you need to learn the proper way to showcase you talents. It takes time to earn the respect and money from others. Good things take time, there are no shortcuts.
Passion alone may not be enough, but if there are no shortcuts you better bring with you.