The main thing also is that the interface of Indesign was year ahead of Quark for a small price. There wasn’t everything (at first typesetting a big book was hard), and it was lacking a lot of feature regarding copy editor cooperation. And no Git was not and his still not a solution for revision :) incopy is using text though, so…

But to be completely honest regarding indesign it took year to be enough for lot of shops.