I wouldn't necessarily assume that. Quirrel seems to like the idea of being out among the peaceful pure stars; a strategy which dooms his earthly vessel is not necessarily such an issue. And while he's slowly slipping away, he can fulfill a few last regrets - such as finally becoming Battle Magic Professor at Hogwarts.
He may like being out among the stars, but that's no reason to cut his fun on Earth short unnecessarily. Like, if the Earth were to be destroyed, and all the horcruxes hidden there with it, he'd regard having the Pioneer horcrux left as vastly superior to nonexistence, but that doesn't mean he wouldn't like to continue hanging out on Earth.
Edit: Also, if he's afraid that someone like Harry could accidentally explode the Sun, taking the Pioneer Plaque with it, he has reason to stick around to stop that from happening. Also, if Bacon's diary wasn't a horcrux, how do you account for Voldemort telling Harry it's nearly indestructible?
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 95. The previous thread has passed 300 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: