The use of Helvetica Ultralight as the system font is a mistake. I
can say this more confidently than my other gripes, as I have my
own 20/15 vision and the opinion of revered typography expert Erik
Spiekermann to back me up on it. He calls the choice a “youthful
folly,” saying that in large swaths at 13-point, the text looks
like a lovely, smooth carpet — and is also completely unreadable.
While iOS does let users adjust font sizes throughout the system,
it may be a bad sign if many or most people choose to increase
them by default.
Really good critique.