When the conversation moves towards topics like this is can be difficult. However, sometimes it helps to try to understand intent.
When someone is asked if they have passion for something, it has a double meaning, both positive and negative.
The negative: They want to work you into the ground. There was a study done on this and it concluded that passionate people tend to be exploited at work.
In another study, participants rated it more legitimate to exploit workers in jobs more traditionally associated with passion, such as an artist or social worker, than in jobs not generally seen as a labor of love, such as a store clerk or bill collector.
This is a REAL problem and we should absolutely worry about it. There's also this as well:
The researchers also found the reverse is true: people who are exploited in their job are more likely to be seen as passionate about their work. Participants read about a Ph.D. student’s working relationship with their graduate advisor. Those who read a scenario in which the student was being exploited – verbally abused and given unreasonable deadlines – rated the student as likely to be more passionate than students who weren’t being exploited.
Then there's issues associated with burnout. The Harvard Business Review wrote about this as well.
In contrast, those with obsessive passion display higher levels of negative affect over time and display more maladaptive behaviors. They report higher levels of negative affect during and after activity engagement; they can hardly ever stop thinking about their work, and they get quite frustrated when they are prevented from working. They also persist when it’s risky to do so (just like a pathological gambler). A reason for this is that their work forms a very large part of their self-concept.
That's a lot of negative, but I wanted to take this opportunity to establish that there absolutely is an interest to exploit people's work and I don't want it to as front and forward in this conversation.
The positive: So, in truth we want to work with people of passion because passion matters in how we do things. Again back to intent. Passion is likely a misplaced use of the word. What they mean is "what has attracted you to this position" and that is an easily answerable question. You can talk about working with people or you really enjoy team work. You might be detail oriented and maybe you like that. There's a lot of sub-skills or areas of an industry that you can find things that genuinely interest you. Sometimes we apply for a paycheck, but sometimes while getting that paycheck we find little things that we legit enjoy doing and also want to be good at (passion!). So I would lean in that direction. I would up front as say:
I don't know if can say honestly, that I'm passionate about the industry. But I like (example of some subtask or element of the job that interests you) and I feel it would be interesting to that in this context.
What I suggest, before any job interview, do some research on the type of work you're applying for and try to find sub-tasks that interest you. When the passion question comes up you can both be honest and also sell yourself at the same time. Everyone isn't passionate about their industry, but you don't need to be. You need to be passionate about your WORK and that's important, I think.