[Jtsummers]

They do address this in the article.

  In fairness, the system deployed in Saudi Arabia — the
  Patriot Advanced Capability-2 or PAC-2 — is not well
  designed to intercept the Burkan-2 missiles that the
  Houthis are firing at Riyadh. The Burkan-2 flies around
  600 miles and appears to have a warhead that separates
  from the missile itself.

[lainga]

Also worth noting that the MIM-104 original and PAC-2 were developed by Raytheon, and I suspect that the PAC-3 was awarded to Lockheed Martin because the PAC-2's problems were so severe.