Honestly I get why they're confused! My grandma still thinks I can fix her toaster because I work with tools. Some jobs you just can't picture unless you see someone in uniform or at a shop. If your work is just on a laptop, it looks like you're just messing around online to them. That whole world of digital work is totally foreign if you've punched a clock your whole life. They're not trying to make you feel weird, it just doesn't compute in their older view of how jobs work.
My friend's mom saw him working from home and assumed he was unemployed. She kept asking when he was going to get a real job with a proper office. It's just a totally different world to some people.