Look at the wording- 'premium experience'. He's not selling coffee, he's thinking big picture of the whole experience from the moment you walk in the store. He's not even wrong here. This is good business management- that he's taking charge of everything about the store from the decor, the furniture, the colors, how the employee talks to you, etc. That's all part of the experience.

What's wrong is that people keep going. Most people don't give a fuck about the experience, they just want a tasty coffee. Our economy is based on competition and free choice. If he makes his coffee cost $8 or $9 or $15 or $50 that's his right and his company's right. Just as it is your right to go elsewhere, which you should be doing anyway.

The thing is- IMHO, Starbucks coffee isn't worth anywhere near $9. Here's a challenge- go to Starbucks and order a double espresso shot. Now find a local artisan coffee place, like the type with a chalkboard that says where the beans they're brewing today were grown. And get a double espresso from them also. Compare the two.
What you'll notice about Starbucks is that it's burnt. And that's because it's literally burnt- the typical Starbucks bean is roasted MUCH darker than average, so the resulting coffee flavor is dominated by a burned smoky bitter-ish flavor.
Compare that to your local artisan coffee place- you'll notice it's NOT burnt, the flavor is NOT dominated by smokiness, but you have a lot more layers of flavor. Then order whatever drink you want- better coffee in means better drink out.

Keep in mind also most of what Starbucks sells isn't really coffee, it's milky sugary drinks that incorporate a few drips of espresso. So you're paying $9 for a sugary calorie bomb made from overly roasted coffee that just makes you fat.

Also- if you usually order the same thing at Starbucks- just learn to make it. Even if you throw $1000 at a nice fully automatic espresso machine, taking the per-coffee cost from $9 to $1 means you'll break even on the machine in 125 coffees. For most people that's less than a year. And you can do it yourself- next time you order, watch what the barista does. They are not wizards and nothing behind the counter is magic. An espresso machine and a blender will make like 95% of the menu. Here's a guide