Kidding aside, I don't think it's such a bad choice. I've looked for open source calendar/todo solutions and they either suck (can't be shared with someone) or can't be self-hosted. So I ended up using a file sync system with a spreadsheet. Worked well for me and my girlfriend to have a shared calendar/todo list.
Very fast to make a quick list, but of course awesome filtering/calculation/lookups etc.
I have a to-do.xlsx for work, and one for home. Different sheets for to-read, to-call etc.