I still think it'd be both a good test of the actual hardware performance beyond its intended/expected lifespan, Putting into a prolonged death dive once they stop gathering data would be a chance for amateurs to develop a community network and people with brains can test out methods of getting better data from the available signal can get a chance they will never get without launching their own gear. Even if NASA/ESA sell a license that will enable full acess except maybe directional control It will help come budget time, but just throwing away functional hardware so fast I don't feel is in everyones best interests.
How many children dream of being an astronaut these days? Whereas letting the community "have a play" will inspire so many people besides the educational opprtunities for tomorrows engineers would be immense. NASA etc can wash their hands completey, "open" the craft to anyone who can transmit and receive with their own gear. Ok it won't guarentee a new patentable technology to make money from but hell in the spirit of sharing (beyond a few approved JPGs)and inspiration it would do wonders. For a start "who" would be allowed to choose a target to turn a camera towards and for how long, the logistics of this alone will take a lot of time and bickering to reach a workable consensus which could become a usable solution for the big space agencies instead political powers having vetos based on personal gain.
Its not like any craft get to locations in our solar system overnight, Mission windows get booked out decades in advance. So why not have the craft take decades to spiral to destruction while nothing else is going to be in the neighbourhood? The public community would make do without being able to reposition craft and it will have tons to contribute and provide procedures for discoveries to be verified. Even just the technical challenge of getting random craft to track items and other craft so we can launch exploration probes out in random directions and have them communicate and funnel information back to earth. Just having eyes out there gives us a vangtage point to triangulate with making early warning detection possible for asteroids etc much faster with better accuracy. Damnit we dont have to only do things because we expect to be paid for it.
Sorry for going off topic ranting. I've enjoyed Rosetta and other missions in recent years and its disheartening to see just how quickly useful hardware gets deliberately destroyed. May not be state of the art or scientifically interesting beyond the mission for the big boys, but for countries without space agencies it could be a foot in the door and show its not as expensive as they thought. Plus what a chance for universities and the rest of us to get some experience and maybe contribute. With the last transit of Venus I spent months planning what I wanted the photograph, how and from where and capture the entire event, it was an amazing experience for me. Plus I got to contribute to a project in Germany that was a modern take on the observation project Captain Cook took part in to get observational data and measurements from around the world and calculate the Earth Sun distance. OK not a scientific breakthrough but an interesting exercise, not one i could contribute to mathematically but I was able to deduce and prove that there were precision errors due to rounding values with the tools used in the project that would make the results bad. It wasnt much of a big deal but it was something I am happy I was a part of and even my small contribution was enough to feel a part of something big. It was published in German (I should try to find if its in print, i got a pdf
but it turned out I was the only person in the southern hemisphere who shot the entire transit and contributed to the project. I learned heaps about the collaboration process andit gave me a huge boost in my interest in astronomy and something meaningless that i am still proud of. To allow ordinary folks to be a part of even dead space missions will do so much for the whole field of astronomy!