> the claim that hypersonic weapons can reach their targets faster than existing ballistic missiles
The majority who are seriously working in these fields do not advocate for such systems based on this class of claims.
> This extreme heating limits performance in two ways. First, it constrains glider geometry, as features like sharp noses and wings may be unable to withstand aerothermal heating.
Everybody working in this field understands this and has various approaches to the problem.
> Second, this heating renders hypersonic missiles vulnerable to detection by the satellite-mounted sensors that the United States and Russia currently possess, and that China is reportedly developing.
Also well-known. While you are going to be thermo-structurally constrained, Boyd's Energy-Maneuverability theory is decades old and relevant to these systems.
> Yet the performance of hypersonic weapons against missile defenses is strategically meaningful only if it offers a new capability (i.e., if these weapons do something existing missiles cannot). This is not the case.
The speed and what it confers is a new capability.
> the technical basis fails to justify the price.
In the U.S., this is more a reflection of the U.S.' failure to maintain its leadership in hypersonics since the 1960s and 1970s. NASP was a disaster of a program and a bad idea (though it did provide huge benefits in terms of learning and technology programs). As is typical in U.S. behavior, upon the cancellation of NASP, there was a slamming shut of funding to hypersonics that undermined healthy sustainment of expertise and facilities. Present-day expenditures are helping the country get out of the pit it entered.
There are a number of valid technical & programmatic criticisms of hypersonic systems and the U.S. hypersonic efforts. This article touched only on cost without any compelling support.
While I'm not a credentialist, neither of the authors appear to be aerospace engineers, and it shows in this article. They would have been well-served by vetting this through people actually involved in the programs referenced.