I think you're painting with too broad strokes by likening all marketing to hacks. Marketing is more like finding alpha in a changing, inefficient market. There are going to be short term and long term strategies that work. The only guarantee is that things will change with time and those with more information will beat those with less.
That sounds right. I look upon the word "hacking" favorably and use it broadly to mean something like "manipulating a system for a particular outcome" rather than just This One Simple Trick, sorry if I wasn't clearer.
I like the guarantee. That's why hacking in the conventional sense today-- which needs constant awareness, involvement, adaptation, experimentation to find out what works, non-codified intelligence, and dealing with the reality of a system -- can beat the process du jour. It might become the new canonical process if everyone else starts doing it.
Sometimes I feel like long-term or well-thought-out strategy is the hack in a sea of self-proclaimed hackers who focus on useless wins and optimizations.