As someone who builds a scheduling product which offers an iCalendar feed for Google Calendar (among others), I have to face this issue on a weekly basis. The

As someone who builds a scheduling product which offers an iCalendar feed for Google Calendar (among others), I have to face this issue on a weekly basis. The most plausible explanation I came up with (and what I tell my users) is that Calendar is maintained by a small team in Switzerland for which this isn't a priority. I don't blame anyone, if true. It might not be easy to fix with little resources. The fact that some feeds sync faster than others (Facebook events) and syncs speed up as time passes, makes for a weird case. Outlook.com or iCloud/iCal sync properly. One of those offer a way out for my users if critical.