Because in a lot of places, OSM has more accurate points-of-interest coverage. I maintain the map for a fair chunk of Soho in London. On Google Maps, I've seen

Because in a lot of places, OSM has more accurate points-of-interest coverage. I maintain the map for a fair chunk of Soho in London. On Google Maps, I've seen places I know about filled with points of interest that aren't actually there, geo-targetted SEO spam and so on. For various bits of London, if the map says it's there, I either put it there or checked it. I just checked an area of London that I maintain for OSM but on Google Maps: it's a load of shit. Shops and businesses that closed years ago still on the map. Large corporations inside police stations. The Victoria Embankment Gardens marked as being in the River Thames.