When it comes to secondary languages we jump very quickly from teaching people "this is an alphabet" to "this is how to use words and sentences in that language". That might make sense if you're using a language that uses more or less the same alphabet (nobody who has English as their primary language is going to struggle that much with the German ß once you tell them it's just pronounced like "ss" when you transliterate it), but when you get to languages where the alphabet and how its pronounced differ significantly from your primary languages that barrier can be hard to overcome. The same can also be said for grammatical rules, especially if they're different compared to yours.
I had ancient Greek in high school and I distinctly recall finding it much more difficult than Latin specifically because the alphabet was so completely different. I did eventually learn how to read it, but the alphabet took me a year to get a grip on, and that's an alphabet with not even that many extra/fewer characters compared to the alphabet used in my primary language.