I understand your concern, but I think there are a few assumptions you make which we don’t know if they are true or not.
First, Tesla here is literally inventing something that was not here before. They are innovating esponentially EVs, self-driving technology, BEV and, now, solar. I’m quite confident that the new inverter is gonna be competitive with Solaredge ones, and the comparison between the new powerwall and other competitors products is merciless.
But you’re right, Tesla is going for wealthy enthusiasts and early adopters. They are doing so with batteries and solar roofs as they did (and are doing) with cars. But Elon said that from the beginning, Master Plan 1. You sell expensive stuff to get more money to invest more and produce cheaper stuff. And the you reiterate, until you have a real mass market product. In your analysis I think you are not taking into account the massive, yuge costs of selling a competitive mass market EV, or solar roof, or battery system. There is no technology yet. More than that: there is no market. They are bulding it, just now (see Gigafactory and Buffalo factory). IMHO, they are trying to go in the direction you mention, but there is no possibility to do so yet. Prices are too high right now, and will be for a few years. A mass market Tesla as you depict would sell millions of EV and batteries and solar panels, and would not have a 200$ stock, but 2000 or even more. We are talking about the in-famous 1 trillion company that many of us dream. Tesla is not just doing software: they can’t leapfrog and become the biggest website in the world in just a few years. The entry barriers in automotive are incredibly high; and solar and BEV is not easier. Long story short, the real chasm is few years from now, and it would mean having totally different prices.