[fuzz_junket]

I'm with you, I think it's hideous. And it's not, as another commenter wrote, just the fact that we're seeing a new font replacing an old one in a particular context. I haven't seen this new font in the wild — just on the spec page — and I still thought "Surely no-one's putting their name to this…"

[Touche]

Can you point out specifically what makes it hideous?

[fuzz_junket]

It's probably a personal aesthetic, but the variable stroke widths make it look cartoony. It's also got a tendency to big loops — the a, p, h, and g in the sample all have very large, arched, oval shapes (this is probably what they're referring to as the large x-height). That makes it look exaggerated to my eye, and doesn't help the cartoony appearance either.

But if it is a personal dislike and other people are fans, I can't object. It wouldn't be the first time I disliked an Apple initiative that turned out to be very successful.

[derefr]

The big loops seem necessary to me, at least when staring at the 8pt size on my retina screen. It's the same sort of contortions you go through to make a "pixel" font look good at 8x8 or 5x5, or an icon look good at 16x16—abstract overemphasis to survive reduction.

I think, if the font didn't literally have to be continuously zoomed in a lot of places, they would just lose the overemphasis at larger sizes.