Yes - branding drives perception which can drive consumer decisions. Consumers can also drive a brand.
Certainly skewing old wasn't the only factor for Cadillac but it definitely was a component and they are trying to spend their way out of that image (both with ads and with more performance-minded cars).
I agree that Apple is an expert at hip but their time dominating is limited. It gets harder to be hip when so many people, especially those much older have them and mom/dad/grandma/grandpa all want to Facetime you. Younger people have been migrating their time away from Facebook because of the saturation.
I disagree on Android and the data doesn't back up your statements. Android is comparable with younger demos [3] and has more market share [1] (esp. outside the US) [2] so they don't "have a monstrous hill" to climb with younger people. Android and device manufacturers are positioned quite well.
It's going to be a challenge for Apple to continue to ask for a premium price when they no longer have a compelling quality argument and Android OS and devices keep getting better with many outperforming the iPhone. People are also getting tired of Apple's closed systems. They are "The Man" but most consumers haven't realized it yet. The squeezing they do with storage is ridiculous.
[1] 52.8% market share in the US, Jan 2016 - https://www.comscore.com/Insights/Rankings/comScore-Reports-...
[2] 80.7% market share globally, 4Q2015 - http://www.gartner.com/newsroom/id/3215217
[3] 52% of millenials have an Android device vs 44% for iPhone, 2014 - http://www.techtimes.com/articles/15084/20140908/draft-andro...