A nice article, but it would have been good to hear more about the specific justifications for shutting the telescope down in advance of JWST's launch. $14 million/year doesn't seem like that much, in the grand scheme of things.
Heck, why shut it down at all? Document the communication protocols and orbital elements, and turn it over to amateurs.[1]
We seem to have put an awful lot of our eggs in the JWST basket.
The telescope ran out of coolant in 2009, but it continued operating for quite a long time after that. The article says that one of the biggest concerns is the difficulty of communicating with it, as it falls further from Earth in its Earth-trailing orbit.
Compared to the 2.5-year mission specification, its lifetime was long. I know NASA over-engineers, and extends each mission as long as some hardware operates (see Opportunity), but that's still an impressive mission lifetime.