I think one of the key points is that "there's never been any secret sauce to the company's battery technology". Tesla very admirably opened up its patents to competitors. Musk seems to want competition in the electric market. It almost seems like he cares more about proving the viability of electric cars than proving that Tesla can be a profitable, multi-billion dollar company.
When you're selling a unique product that appeals to a certain subset of the population that other products don't appeal to, it's easy to get those early sales. People who believe in Tesla will forgive not having a local dealership with repair shop. They'll forgive faults in the vehicle. They'll forgive a high price that can't be negotiated down. They'll forgive trade-in prices that are probably lower since Tesla doesn't have dealerships to resell the vehicles and probably just sends them to auction.
As they try to reach more customers, there are many things that cost money that they'd have to go for. And maybe it would work.
However, I think if electric cars catch on, it won't be hard for other companies to follow suit. I think a lot of companies just don't want to pour money into a very expensive battery that will make a vehicle unprofitable. If the economics change, other automakers will follow suit and there's little to no barrier to entry.
None of this is to say that I think Tesla is doomed. It's more to say that I don't think Tesla is going to become one of the top 5 auto makers in the world. In fact, it's unlikely that Tesla will break the top 15 (Mazda sitting at #15). And if it doesn't break the top 15, is it really worth $27B? Mazda comes in at around $11.6B with very healthy profits and a full line of vehicles with dealerships around the world. I think Tesla would be incredibly successful if it sold 1.3M cars in a year. As of 2Q2015, Tesla had sold fewer than 12,000 Model S vehicles in total - ever, not just for that quarter.
So, I think it's possible that Tesla will become a Mazda. But if it becomes a Mazda, it's worth a lot less than $27B. And what are the chances that Tesla will become a Mazda? Even if one thinks Tesla is a great concept led by great people with a great product, the odds are bad that Tesla will gain the market traction that Mazda has.
I think there's a middle-ground where one can say that Tesla isn't a joke or doomed or anything like that, but it's really hard to justify such a sky-high validation. There's no barrier to entry that software companies have. There's no network effect they'll exploit to make a quasi-monopoly. And there's serious competition. Competition that ships a lot more volume and can probably move into electrics the moment Tesla shows them the market and economics are right for it. That doesn't doom Tesla. It does make it unlikely they'll become so big and profitable.
But that also doesn't mean that Tesla won't have a big impact on our society. At the very least, it's pushing the conversation about electrics forward and showing us a vision. It might not be a vision for everyone. It might be a vision for the elites for now. But it's daring and interesting and there's something worthwhile about that - especially so for Musk. It just might never be worth its current market cap.