Basically the start of their downfall was Trian Partners, an activist investor, bought $2.5 billion of GE stock in 2015 with the express goal of GE taking on a ton of debt to do share buybacks and raise the dividend
https://steveblank.com/2017/11/01/why-ges-jeff-immelt-lost-h...
Karma's a bitch.
This very article is about them divesting the lightbulb business which, according to the linked statement from GE themselves, will happen in mid-2020.
I suspect part of the reason they're getting out of a lot of this commodity (or borderline commodity) businesses is because they make much more money on building power plants and wind turbines, jet engines, medical equipment (MRI/CT/PET/etc machines and more), etc.
Some quick digging, and it looks like their lighting and industrial controls division made all of $300m in profit. Their aviation products alone profited over $28b.
If I were them, I wouldn't care either.
Curious what others think, but I think they undervalue the brand value they are eroding by divesting from all of these low growth business that were the building blocks of their once great brand?