It's jarring initially, but becomes natural very quickly. Writing loops like "for i in 1:length(arr) ... end" is pretty neat compared to C++ or even python. Plus in math sequences typically start at index 1.
Most modern languages have a «foreach» operator or its functional equivalent as a collection item generator. «foreach elem in my_collection {}» also has a clearly defined semantics: «process everything». The code is cleaner, concise and a bit shorter and reduces the cognitive overload. And since many languages now support lambdas, the code can quickly and error free be converted into a staged data processing pipeline without the use of temporary variables that serve no purpose, e.g. «foreach elem in my_collection.filter (_ -> _.my_selection_criteria ("42"); ) { do_something (elem); }». Whether the collection is indexed from 0 or from 1 becomes irrelevant.
Assuming that arrays start at 1 is a source of occasional bugs in public packages. The existence of OffsetArrays means that arrays can start at any index (so for people who get nauseated by 1-based arrays, you can change it).
Instead, write "for i in eachindex(arr)".
In fact, Julia’s array syntax means you can loop over and manipulate arrays without using indexes much of the time, so don’t even need to know how they’re based.
I'm not quite sure that this is the case enough to say "typically". In terms of undergraduate exposure to math, I think more people have taken Calculus (or Analysis) than Linear Algebra, and I think Calculus textbooks tend to index from 0 while Linear Algebra textbooks tend to index from 1.