Tesla killing Solar Roof is leaving installers with six-figure losses

Their solar shingles looks like regular shingles and install on the roof the same way as regular shingles. Installers just need to be regular roofers with some extra training to handle the peculiarities of solar shingles. I don't know about GAF but the extra training for CertainTeed can be done online.

Compare to Tesla Solar Roof where the physical installation requires completely different skills. As a result there are way more crews available who can install GAF or CertainTeed solar shingles than Tesla roofs.

The Tesla roof tiles are more efficient than the solar shingles and they cover the whole roof, whereas the solar shingles usually don't cover the whole roof, so the Tesla roof usually generates more power.

GAF is 140 years old and CertainTeed is 122 years old, and making building materials is their main business. This makes them a lot less risky than Tesla was. If they ever decide to stop doing solar shingles it is almost certain they will handle it better than Tesla since their core business depends on keeping roofing contractors happy. They will almost certainly keep repair parts available, crews will remain available for maintenance.

Even if decades from now replacement solar shingles are not available any dead solar shingle can be replaced with a regular shingle and an electrician can adjust the system accordingly. When the roof reaches end of life and needs to be replaced, you just need an electrician to de-energize the roof and then removing it is just like removing a regular roof.

The Tesla roof on the other hand requires a special crew, both for repairs and replacement. Removing the roof is a much more involved process than removing a solar shingles roof.

This is likely going to screw existing Tesla roof owners. With Tesla actively in the business it was seen as a premium feature, bumping the market value of your house by maybe 5 or so percent.

Now buyers will see a house with one as a potential maintenance liability that will be a nightmare when it reaches EOL. Sellers may have to offer a substantial discount to sell their houses.

It comes down to GAF and CertainTeed treat it as a roof first which has solar technology, whereas with Tesla is more solar technology that is a roof.

Its about hype farming so idiots take leveraged positions in the stock and get wiped out.

If you see Elon saying something particularly distasteful or stupid he is collecting puts to liquidate.

As with so many, their weaknesses are also what made them stand out initially.

tl;dr - It's driven by internal room shape requirements (plus weak planning; in some jurisdictions "no, that's an eyesore mess, redesign it" it a thing in planning, but I gather largely not in most US juristicitions).