I think you missed the whole point of the excerpt.

Her wording was carefully crafted to say he is controlling (not protective). Fergie went triple platinum with the Dutchess and would easily do so again given the same backing as last time and the B.E.P. group and fans support. William doesnt want that because he could not achieve the same solo with his album (which was shelved)

However he is a great producer and musician.But a solo album from him would more than likely include a guest feature on every track, unlike Fergie.

It seems like its almost the same situation as The Fugees with Lauryn Hill and Wyclef. And that is not to compare Lauryn Hill to Fergie, just situational similarities.