It's because ‘Rockit’ was made by Bill Laswell, Michael Beinhorn, GrandMixer DXT and three other guys on turntables. Hancock basically turned up at the end to play some synth lines.

Laswell and Beinhorn were in the band Material, and turned it into a production outfit, plus Laswell was a producer at the label Celluloid at the time, which label was a pioneer of hiphop. He also participated in the New York no-wave jazz scene as musician and composer.

Hancock was in his early forties, and his career was getting stale. His manager, twenty-five years old, pitched the idea of making a track to both him and Laswell. Hancock was taken by Laswell to hear some popular djs, but still required more coercing by the manager.

Material's early stuff might be closer to ‘Rockit’, although it's more disco-funk. Dunno about Celluloid's output, as I'm not really into old hiphop. Laswell used scratching in some of his genre-clashing projects well into the 2000s, e.g. in the ‘Axiom Sound System’ concert with Tabla Beat Science and a bunch of other folks (including Grandmaster DXT). Laswell also co-produced and played bass on the rest of Hancock's ‘Future Shock’ album and the next two albums ‘Sound-System’ and ‘Village Life’, and did other collaborations with him.

(Yall might be familiar with Time Zone's ‘World Destruction’ with Afrika Bambaataa and John Lydon; and Material's ‘Seven Souls’ with the voice of William S. Burroughs. Both of these were featured in ‘The Sopranos’, and both were produced by Laswell, just like PIL's album ‘Album’.)