Plus it was literally the most anticipated game of the year by a wide margin, which means that they were also under enormous pressure from the retailers and the general public.Pretty much. Unless they're blind, everybody on the inside a project can see the bug lists and problems when they run it. They all would like more time to work on it. Up to and including infinite time (you can fix bugs forever, it turns out).
It's the people outside that circle who want to make money, pay the bills who say "No, we need to ship it and make some money." Executive types make that call.
CD Project Red hasn't released anything big since The Witcher 3. Maybe the Gwent game made them some easy coin, but they were probably bleeding cash to make CP. Exactly the kind of pressure to release a game before its really ready.