Considering that Elon Musk has been speaking of "production hell" for a few months now, I don't find it at all surprising that Model 3 production is delayed. Musk's timelines have generally represented best case scenarios involving optimal execution by all parties. As the intention was to keep the Model 3 relatively simple and to stay on schedule, I expect the Model 3 will be delayed by only weeks or months, rather than by years like the Model X.
As a consumer, I wish that Tesla's public timelines could be more conservative and thus accurate. However, it seems that, by creating very aggressive, public deadlines, Musk feels that he can motivate his employees to push harder and achieve more. This makes sense to me, because if the goal is to provoke intense focus and achievement, there's nothing like a critical mission with tight deadlines.
There's really no question that Tesla has remained on the vanguard of EVs. For those who desire the capabilities of the Model 3 in the $35K - $60K price range, there is still no competition (aside from used Model S cars). Well, there's the Chevy Bolt and the upcoming 60 kWh LEAF, but not if you want long distance capabilities or high-end looks.
Once the market has matured and multiple OEMs are selling EVs that can fully replace ICE vehicles, and once Tesla Energy products have become more mainstream, it may make sense for Musk to scale back his role at Tesla and let a more traditional chief executive take over. I hope that Tesla survives the transition from upstart automaker to mature, diversified company. Even if it doesn't, I expect that the Tesla brand and Supercharger network will carry on in the hands of another corporation.
Also, for what it's worth, I had mixed feelings on the SolarCity acquisition. I believe it was essentially a bailout and that SolarCity had serious issues. On the other hand, I think that it was strategic for Tesla and has long term benefits - the only question is whether TSLA shareholders paid too much for SCTY. Tesla Energy has a great deal of promise and it really does make sense to have solar and batteries under one roof, installed for customers as integrated systems. In the future, we should also see more integration between home/commercial solar PV and EV charging, whereby EVs plugged in during the day should be able to soak up "excess" solar production.