I think it was pretty reasonable of them to worry - lots of people who don’t like spending unnecessary money also don’t like spending not-obviously-necessary money on safety equipment, and there’s plenty of material on the internet that would imply resin printing is completely safe as long as you don’t drink the stuff. Resin printing with woefully inadequate ventilation/PPE is really common, so it’s a pretty safe bet that anyone asking questions is probably also doing something unsafe without realising it, especially as resin not liking the cold is something a lot of people learn about fairly early on (unless they live somewhere where it never gets below 20°C).