The market shifted. Solar used to be a luxury product, with only some environment-conscious rich people putting them on their roof. In that market the solar shingles made a lot of sense.
But solar has become a commodity product. Panel-wise the big bucks is in massive industrial greenfield installations, but Tesla's private-label brand can't compete on that market. In the residential market they are competing with every single local contractor who's willing to make a few bucks throwing bargain-bin panels on your roof, and their own system of proprietary panels and subcontractors can't compete with that either - especially when they force you to buy a power wall as well.
But solar has become a commodity product. Panel-wise the big bucks is in massive industrial greenfield installations, but Tesla's private-label brand can't compete on that market. In the residential market they are competing with every single local contractor who's willing to make a few bucks throwing bargain-bin panels on your roof, and their own system of proprietary panels and subcontractors can't compete with that either - especially when they force you to buy a power wall as well.