Except one ingredient is missing: most people cannot afford one, even if they tried really hard.
And then the economies of scale (and hopefully competition) will kick in and it should reach a point where nearly every new house, and nearly every replacement roof, will be solar by default. At least in climates friendly to solar.
IPhone got a lot of attention when it was released, but it was a while before they became common with more than just the early adopter crowd. This might take a while longer for various reasons, but still, this is a big deal.
This has an interesting twist. While it is subtle, people can tell you have it. People like to impress their neighbors. But this one isn't just "look how much money I have" but "look how I am using my money to be a responsible citizen of the planet." If you are going to try to enter the "keep up with the Jones's" race, this isn't a bad way to go about it.
I think this is key - often the pitch that "sure, it's expensive up front but will save you money in the long run" falls on deaf ears when people don't have the disposable income to immediately absorb that large up front cost, but when you're buying a house in most cases you're already taking out a large loan to finance a big up-front cost.
The advantage, of course, is the 0/low upfront costs.
Whether or not this model works for the roof tile system is another question entirely. Of course, the bill would be much larger, but the tax credit might be larger as well.
I'm not sure how they handle a circumstance in which your income causes your tax credit to be phased out. Likely there's fine print where you have to pony up extra money.
Relative to the benchmark of "People who can afford to buy a home in the US," perhaps a solar roof is not so unattainable. It just has to look great, convey social status, and be durable.
Most US home owners don't pay for their house (or car) outright. The putative purchase price of photovoltaic panels may not be prohibitive even for plebs.
And factoring in subsidies, electricity cost savings over a period 5-10 years, it might be more affordable than you think.
High end models few can afford at first, then slowly moving into the "regular guy" market once the R&D is done and mass production bottlenecks are solved.
$500 is not that much more expensive than a Nokia device at the time, and well within the surplus that a good chunk of people have to pay - especially when subsidized by carriers.
$30 000 - $100 000 - is another ballpark entirely in terms of cost. And it has to work out economically or it won't get anywhere, many ingredients are needed to make it work right.