Tesla doing everything in-house does not explain Musk's success IMO. One might say that picking the brightest people, whether they are employed by an OEM or being committed externally makes more sense business wise. That Tesla decided to go fully electric whereas other carmakers were still lobbying governments to go easy on emissions, THAT gave Tesla an important head start. Not only will other car brands catch up soon enough, one might say that Tesla ONLY swapped the ICE for battery drive. There is so much more to do when it comes to clean, green and efficient Personal Mobility. In that last respect, Tesla has proven itself pretty conventional. The Personal Mobility sector, the world's largest consumer market btw, should have challenged more OEMs to step up to the plate from other sectors by now - I have often referred to this as "Next-Gen Mobility is much more a GE than GM affair".
