In my case, I work for a big company doing work that I really enjoy, but have a bit of golden handcuffs going on. A smaller company working on something that I'm really excited about invited me to come visit, mentioning that they're wanting to grow their team. It's possible that this company could make such a compelling case that I want to join, but at the moment it's hard for me to imagine leaving the security of my current position with a brand-new mortgage hanging over my head. Trying to decide if accepting the invitation to visit but declining to interview afterwards would burn bridges or close the door should I later want to apply.