Disappointing yes, but not unexpected these days. As noted on the Watch Dog’s blog, the reasoning was mainly polish:
We struggled with whether we would delay the game. But from the beginning, we have adopted the attitude that we will not compromise on quality. As we got closer to release, as all the pieces of the puzzle were falling into place in our last push before completion, it became clear to us that we needed to take the extra time to polish and fine tune each detail so we can deliver a truly memorable and exceptional experience.
In that case Ubisoft, I do hope to see less errors on the PC version.
I’m not going to bet on anything though.