That's the point of this article, but honestly it seems to be neither here nor there. Being disconnected from business goals happens with or without agile. Agile can only solve delivery problems, not defects in business strategy.
It's not that customers don't "get to". It's more that customers don't "have to" because they can see working software coming out of the team, and they are confident that things are progressing.
There are no "rules" in agile that says who can do what, just teams of people negotiating what works best for them. "Individuals and interactions" over process.
As a customer, you get to decide what you want to buy, and you get to be happy or unhappy with the delivered product.
But you don't get to control or even monitor the work in the factory/kitchen/etc.
That's instead the job of a boss! Of course, an agile team also has a boss. But it's not the customer.