- one line per event, so good luck finding multi-day events like “Grandma is visiting”;
- rigid metadata (dates, week numbers, weekdays) stored right next to the editable data (events), so copy-pasting errors are inevitable;
- the most important feature of the real calendar software (reminders) is thrown out;
- grepping is really not how most people interact with a calendar.
If you’re ready to ditch reminders, attachments, locations, use the paper diary planner. At least it won’t let you screw the dates with botched copy-paste.
Update: also, sorting by date must be done manually, my god.