One other consideration that hasn't been mentioned yet is the importance of disabling any radio transmit capability.

For instance, for the Rosetta mission:

ITU regulations require us to permanently switch off the craft’s radio transmitter at end of mission. Since Rosetta wasn’t designed to have its transmitter permanently off, we had to change the on-board software by patching it.

https://blogs.esa.int/rosetta/2016/09/29/how-rosetta-gets-passivated/

It is difficult enough to communicate with things in space at great distances. Having a dormant, tumbling spacecraft with a possibly malfunctioning local oscillator trampling all over the spectrum in the same solid angle as a functioning mission could be problematic.

Then, if the transmitter needs to be permanently deactivated, the options for any future productive uses of the spacecraft seem fairly limited.

One other consideration is the importance of disabling any radio transmit capability.

For instance, for the Rosetta mission:

ITU regulations require us to permanently switch off the craft’s radio transmitter at end of mission. Since Rosetta wasn’t designed to have its transmitter permanently off, we had to change the on-board software by patching it.

https://blogs.esa.int/rosetta/2016/09/29/how-rosetta-gets-passivated/

It is difficult enough to communicate with things in space at great distances. Having a dormant, tumbling spacecraft with a possibly malfunctioning local oscillator trampling all over the spectrum in the same solid angle as a functioning mission could be problematic.

Then, if the transmitter needs to be permanently deactivated, the options for any future productive uses of the spacecraft seem fairly limited.