Lots of starters from scratch

I see a lot of folks on here making their starters from scratch but also talking about friends and family who make sourdough. I'm curious, why aren't more people asking for some of other people's starters when sourdough has become so popular? Is it the satisfaction of making your own? Not having easy access to someone else with a starter? Or something else? If you started a starter from scratch, share your thoughts :)