I'm been in the business for a number of years, and we'll still fighting dumb cross platform compatibilities with the big boys, CMSs (Content Management Systems) and local silos.
Having to build custom hacks and excessive filtering to communicate with these islands is just wrong.
Even good folks like Google and Facebook don't do it right. Maybe because they are in a hurry, or maybe they don't care. That's why we are highly active in setting the calendaring standards in places like calConnect and the IETF (Internet Engineering Task Force). The outputs from common CMSs are also a mess. Quite frankly even worse, not on purpose, just lazy uncontrolled sloppy development.
Those of us that promote connectivity and DO NOT have market power like those de facto stand-alone monopolies, do care, and so do their USERS!! Their own users don't use their calendar communications capabilities becase they don't work reliability across platforms.... they suck there. Just imagine if I had to force you to use gmail because my totally standard email program would not connect to Google's solution. It exactly the same.
So by not adhering to the calendar standards, or by partially implementing them to show a BROKEN yet token compliance, the big guys are actually putting themselves at risk because their customers want calendars that connect and communicate.
Look what happened to companies like Novell when they were the last to adopt TCP/IP!!!
Proper iCalendar formatting and correctly implemented CalDav as the transport mechanism are what will enable the next leaders in the emerging "Time-Centric-Web" (to be discussed later). Something all of us believe in here at dotCal, including our business-2-consumer customers which utilize our products & services to communicate and market in new and interesting ways.
So big dudes, CMS developers, silo sites, your uncommitted approach to supporting the current & developing calendaring standards may help you in the short term, but look out, the "Time-centric" web is on its way.
Danton