Personally, I very much dislike the conversation starter “So, are you here for business or pleasure?” and unfortunately, it’s something I come across a lot. I know it’s just small talk and people being polite, but it irks me for many reasons.
For one, why does it have to be one or the other? A lot of people like their jobs and they derive pleasure from it. Travelling just happens to be a part of that, in which case it’s both. Also, people occasionally travel for terrible reasons, for example a funeral, in which case it’s neither. How do you answer it then?
I think a better thing to say would be “I hope you’re having a good trip.” That way, it isn’t a question, but it invites people to answer should they choose to do so. I get that some people love to share, but not everyone is like that, in which case the question is hard.