Yes, in my opinion they are two different things: following your passions is almost always good, but expecting that to also guarantee you a job can be, many times, naive.
I think the key point is understanding that difference, and being able to decide for yourself how the two should intersect in your life. And that always needs to be done realistically.
I will also say that I personally dislike the idea of having a job related to my passions. They are my passions and in many cases taking a job related to them can condition the way I have to approach them. This tends to happen more with "creative" passions, but you know. Always working, not always for money.
I think the key point is understanding that difference, and being able to decide for yourself how the two should intersect in your life. And that always needs to be done realistically.
I will also say that I personally dislike the idea of having a job related to my passions. They are my passions and in many cases taking a job related to them can condition the way I have to approach them. This tends to happen more with "creative" passions, but you know. Always working, not always for money.