But indeed, the US currently has no capacity to grab satellites from the orbit, so they just could have deorbited the satellite, if they wanted it to be destroyed in a safe manner.
And the US had no capacity to grab submarines from the bottom of the ocean. Right up until they did!
This satellite series had operational lifetime of 6 months and this one has been launched back in 1982. It has been dead with no means of external control for ~40 years.
Now it's extra dead with no means of external control.
You could even say it's like a zombie, with the potential of turning more of the currently "living" satellites into more of its own, eq. to more rapidly expanding debris clouds.
Because if the US did have that capacity you or others on here would know about it already.
Exactly. See also "The Jennifer Morgue" for a fictional take on it by cstross.