In the United States, the majority of the cost isn't the panels. Install needs to get more affordable. More modular, with roofs made to accept them. But, as I said in another comment, I expect most solar to go to big solar farms, where install costs are negligible.

Its also the issue of housing affordability, if you have young families moving into small dwellings that they have to upgrade out of in <5 years time then most solar installations are not going to repay themselves in that timeframe. Therefore its logical to not install solar until you are in your forever home.