To disprove your last point: I'm curious as to how you achieved such a degree while using "till" as shorthand for "until". Are you sure your Bachelor's wasn't in agriculture? ;)

Joking aside, I think it's a consequence of English being a very complicated language with all sorts of borrowing from different language families. There's almost no such thing as "correct" English, and attempts to reason about it in a prescriptive rather than descriptive manner will almost certainly fail. Whether that's a good or bad thing is up for debate, but mistakes happen either way, and I reckon the average English speaker to be a bit more cognizant of that, recognizing that nobody - oneself included - really has a perfect understanding of the English language.