When Apple announced that the next version of OS X, Yosemite was to use Helvetica Neue instead of Lucida Grande, I was disappointed, but not surprised. The inevitable harmonising of OS X and iOS has meant the former taking design cues from the latter more recent system.
Helvetica looks nice in lighter and heavy weights shown large, but for small menus like this I detest it. Lucida Grande may have been missing an italic version, and looked clunky in bold above 14px, but it works well as an interface font. It also had some character, without being in your face. In a small text context, Helvetica is the absence of character, a bland ‘default’. A nothing.
Fast Company interviewed Tobias Frere-Jones, who identifies the problem with Helvetica succinctly:
Despite its grand reputation, Helvetica can’t do everything. It works well in big sizes, but it can be really weak in small sizes. Shapes like ‘C’ and ‘S’ curl back into themselves, leaving tight “apertures”—the channels of white between a letter’s interior and exterior. So each shape halts the eye again and again, rather than ushering it along the line. The lowercase ‘e,’ the most common letter in English and many other languages, takes an especially unobliging form. These and other letters can be a pixel away from being some other letter, and we’re left to deal with flickers of doubt as we read.