You don’t when you buy a car so why would motorcycles be any different?I think we should have the option to choose the tyres when we buy our bikes. That would please everyone.
OEM tires are different than non-OEM and are built to a (very) low price point. The OEM Rosso III on the Ducati Supersport only lasts between 2500 and 4500 miles and fall off handling wise very quickly but the non-oem ones last 2k more and keep feel their entire life.