Sure, they might not. But he gives no basis for saying that other than what he "believes."
People in this community, and on the Fediverse in general, seem to be strongly anti-AI and would like to believe things that make it sound bad and unprofitable. So when an article like this comes along and says exactly what you want to believe it's easy to just nod and go "knew it!" Rather than investigating the reasons for those beliefs and risking finding out something you didn't want to know.
If the model is cheaper to run then they are able to reduce the price without reducing profit, which gives them an advantage over competitors and draws in more customer activity. OpenAI is far from a monopoly.
I based my argument on actual numbers that can be looked up and verified. You "believe" that they "seem" to be doing something else. Based on what?
And perhaps even more importantly, the per-token cost of GPT-5's API is less than GPT-4's. That's why OpenAI was so eager to move everyone onto it, it means more profit for them.
Okay, make it sound worse and even more unprofitable.
Making their AI models cheaper to run (such as by requiring less electricity) is one step along that path to profitability.