Hi Angilion. It's a fair question and one that is asked annually. Give or take the Islamic calendar is the same length yearly (much like our Gregorian calander with the occasion leap year). [..]
Yes, but it's the wrong length. That's why ramadan drifts significantly from year to year.
It's only a point if you think the total hours and minutes spent fasting is important. If that isn't an issue then the varying daylight hours isn't a big deal either. [..]
Using that argument, everybody fasts for the great majority of every day except perhaps people in hospital being fed solely intravenously (are they fed constantly?). So yes, obviously the amount of time spent fasting matters. Fasting for 4 hours is very different to fasting for 14 hours, especially when the fasting includes water deprivation as well. Also, my point was, as I said, the result being that different muslims are treated very differently by ramadan solely because the Earth is (almost perfectly) spherical. Should two muslims be treated very differently solely because they live at different latitude?
Well the founders of Islam probably weren't aware of it,
Maybe not, despite the fact that it was known long before they were alive.
though there is a workaround now of just using Mecca time instead. [..]
I think that makes more sense in context(*). Picking one time makes it equal for all muslims and their holiest site would be the most suitable place for setting that time. Not directly, of course, since that would still be widely unequal by location. When it's daytime in Mecca it's nighttime in many other places, for at least part of the day/night. You'd have to do it by decree, e.g. "On such and such a day, fasting is from 08:38 to 19:02, on the next day it's 08:35 to 19:00", etc.
* I think little if anything about any religion makes any sense, so I'm talking about internal consistency.