I'm of two minds about this.
The first is the one that had so many wonderful and valuable experiences out on the playa and considers it such a special place. How dare someone without the proper deference for that special place come out and ruin it. So I understand where the criticism is coming from, but...
The second is that Burning Man is about inclusivity and impermanence. It's what made the event so special in the first place. What was isn't unimportant, but maintaining it as anything other than a memory is. Like meditation, what is in the current moment is what's important. And lamenting change prevents fully embracing that new experience.
What strikes me as necessary to "save" Burning Man from being "ruined" is to embody the values of the event. Be as inclusive as possible and embrace the impermanence of the event. Meet exclusivity with increased inclusivity. Meet clinging to past experience with increased focus on embracing the present moment. New burners won't understand what the event is about and old burners will have forgotten. Inform/remind them by example, not by condemnation.
I don't like thinking about anything having been lost. That's clinging to the past in a way that feels antithetical to the Burning Man ethos. Every year, many burners will ask themselves, "is this event still for me?" I started answering, "no" a few years ago. But that doesn't mean I think Burning Man was ruined or has failed. It and I have evolved in ways that are no longer compatible. It's changed me and I like to think that, in my own small way, I helped change it. And as much as I'd love to still be in my 20s and still experiencing all the wonder of those late-90s burns, that reality doesn't exist anymore and pining for it only creates craving and misery.
The article should mock (or at least not dignify) people who believe that something has been lost. Those people have forgotten the purpose of the event. Listening to a beautiful song can be a sublimely moving experience. But you cannot capture that experience by choosing a single note and prolonging it indefinitely. And yet people believe they can capture their experience on the playa and relive it year after year. The song changes over time and eventually ends. Acknowledging that doesn't make it any less beautiful.