This joke was made because Patriot missiles came to prominence during the Gulf War in 1991 by providing missile defense against the SCUDs in 1991. Now we’re hearing that Patriot missiles took out 6 Russian hypersonic missiles fired against Ukraine so this joke now has a renewed relevance.
The joke was based on the claims by the US President of the time about how effective the Patriot Missile System was in that they never missed their target.