I think the assumption of the author is that the folks who run Apple will be seduced by profits generated by the financial arm and start emphasizing that more. Which if anyone knows anyone who works at Apple is ridiculous in the extreme. Alternatively, they take on more balance sheet risk and then the whole company is jeopardized by a financial volatility event, e.g., a big jump in interest rates.

Tim Cook and others do seem to be playing a game of chicken with congress. How long can the US division continue to borrow to find the dividend while those enormous piles of cash remain offshore?

I agree with your sentiment. The cash, even if overseas is still highly liquid and readily available.

The author though is trying to get across that certain financial instruments can have a negative multiplier effect.

Imagine a day where the S&P 500 drops by 10%, perhaps during it Apple Capital starts to liquidate a few investments. Let's say the next day is worse and we see another 12% drop. Depending on their hedging, diversification, asset class, investment type and liquidity, it could turn out to be a very bad day for Apple Capital enough to where it affects Apple Inc.

Obviously the above example is extraordinary and we're talking about highly sophisticated financial engineers but we are technically living in an extraordinary time. US Equities have not performed this well in a long time - perhaps since 1997.