That's all well and good, but the calendar nokia made uses some ridiculous one-off backend, can't sync to anything at all reliably, has a completely useless tasks/notes setup, and has several (already mentioned) bugs rendering it nearly useless to a serious user.

Fine, you say, write a better one. That is a bad response, since the bugs the current calendar suffers are all fixable if they'd just open-source the damn thing. There is literally no possible business advantage nokia can be getting out of keeping it locked down. Instead of nicely integrating caldav into the existing calendar, I'm having to kludge a whole series of packages that try to work alongside this thing and work around its stupid timezone bugs.

I'd even prefer a non-redistributable license as long as I could see the source at all so I don't have to spend hours reverse-engineering bugs just to isolate problems that shouldn't exist.