Young kids didn’t have trouble with Logo when it was popular. I remember Logo from my childhood. Negative numbers are not difficult. You just have to think of them as left 5 or down 2.
I remember being introduced to negative numbers in sixth grade! Completely ridiculous. I was in fifth grade and was in one of those shadow days, where I followed a sixth grader around for the day. I was in their math class and got taught negative numbers, and I just remember thinking "wait, why is this just now being introduced?".
Yes. Most children intuitive understand addition and subtraction of negative numbers. It’s just moving left or right of the number line. It’s multiplication and division of negative numbers that’s a bit confusing.
A cursory Google search shows that negative numbers are introduced in 4th-6th grade. For me, I only remember that particular instance of shadow day and just remember it seeming novel at the time (in terms of it being taught). I actually don't have much recollection when things were introduced outside of that until later in junior high or high school. If I remember right, it was specifically about negative numbers, and from what I recall it was me thinking that it was just subtraction or something along those lines.
I'm not an expert, but humankind developed math for thousands of years before negative numbers were discovered. Even irrational numbers were discovered before negative numbers. Furthermore, in all curricula that I know of, addition and sometimes even multiplication is introduced at least a year before negative numbers are introduced. These facts strongly suggest that negative numbers are non-intuitive to young children. Personal anecdotes about peoples' experiences with Logo notwithstanding.
Do note that subtraction and negative numbers are not the same.
Natural fit with algebra.
Someone else in the thread pointed out that Scratch does the same.