That's only "fair" in a certain, academic sense, which claims that willingness to pay more money makes someone more "deserving" - completely ignoring socioeconomic status.
That also offends a lot of people who oppose the above reasoning.
How are concert tickets different to airplane tickets?
Allocation of scarce resources is based on demand for them, expressed in monetary terms. "Deserving" has nothing to do with it. I may deserve a ticket, but not even want to go.
The answer is mentioned in the article. Not all concerts want only people with means to attend. The venue might want to be accessible to low-income members of the community, or it might be a benefit concert, with free tickets and a donation drive.
You can't hand out money (which you're doing if you're giving away something of market value for nothing) without taking on the responsibility of deciding who gets it. Even charities have to put in the work.
That also offends a lot of people who oppose the above reasoning.