They weren’t going to keep a huge 30 pin connector for two extra iPhone models or spend two years on microusb just to quickly switch to usb-c. And I think they went with the 40-pin over micro-usb as they already had a base of consumers with those cables from the success of iPods. If Wikipedia is correct micro usb was only announced six months prior to the original iPhone.
They weren’t going to keep a huge 30 pin connector for two extra iPhone models or spend two years on microusb just to quickly switch to usb-c. And I think they went with the 40-pin over micro-usb as they already had a base of consumers with those cables from the success of iPods. If Wikipedia is correct micro usb was only announced six months prior to the original iPhone.