I agree to an extent, but I don't really see the problem either. If I book a meeting or something through any calendar application, the timezone will be fixed to the local timezone. Let's say I book it for 13:00 in my calendar, it will show up as a meeting at 14:00 in their calendar if they are +1 from me.

So whenever I specify a time with someone that could be in a different timezone, I would either make sure that I am using some application that solves it for me, or I would AT LEAST include the timezone.

Maybe I'm just not encountering the same problems that you do.