I don't think the biggest problem is leading with the "what do you do?" question, or even being a person that somewhat defines their life around their work or career. I think the bigger problem is a lot of people are inherently selfish.
"What do you do" or even "what do you do for fun" tends to be a leading question because you want to talk about yourself, what you do, what you like or understand what you can get out of it.
I don't think there's anything wrong with being at a conference, say, where we're all somewhat defined by a subject or interest and someone asks what you do. It's just very dull when it feels like they're aching for you to finish so they can explain how great they are. Or they're immediately angling for the opportunity to pitch to you, or make money from you, or tell you how further ahead in life they are.
IMO, by all means lead with a question about someone's work. But take a genuine interest in their job and their life. Ask questions. See if you can go for ten minutes without mentioning yourself. If they're not a fan of their role and you're genuinely taking an interest in them, it's incredibly easy to pivot into "what do you do when you're not studying gorillas in the Congo?!"