Like, once a Starbucks drinker goes out and buys a heatgun to roast their own beans they will discover the truth that has been hidden from them all along.
I always just assume that someone who drinks Starbucks regularly would be the most aquainted with how it tastes and might not need someone to tell them.
Making a consistent product year over year with inconsistent raw materials, in high volume with wide distribution, and maintaining prices most people can afford is very difficult.
Sure you can get better coffee if you spend time doing research and sourcing beans and roasting equipment, but that doesn't mean there is no place for Starbucks in the world.
On the other hand, Starbucks keeps spreading to smaller cities. So they seem popular with someone at least.
Poor quality beans and robusta are ‘hidden’ with a dark roast as the flavour moves to bitter. This also lasts a long time and doesn’t go stale for ages. As a general rule in coffee, light roasts have a variety of tastes and dark ones are just bitter. This saves a lot of money. Low quality arabica beans are less than half the price of good ones, and that’s for me, purchasing a few kg at a time. Starbucks will be using a lot of low grade robusta and that stuff cheaper again. Combine this with a brand which makes coffee where the dominant flavour isn’t the coffee but the milk (if you can call miscellaneous juiced nuts etc that) which is often flavoured. I don’t think the coffee will be their primary cost in consumables, I’m guessing milk is. If you want to have a play, get a heat gun and a kilo of beans. Have a play about with different roast styles. It’s a slippery slope but it isn’t an expensive one.
Edit: Here is a link with a breakdown of Starbucks costs. Not sure how accurate it is, but it puts the coffee as 16c per cup, and the milk at the same. The cup itself is about 32c according to the article. http://coffeemakersusa.com/pricing-breakdown-cup-coffee/