Did Cleveland make the wrong choice by not drafting Derrick Williams?

While Kyrie might be a little better player now, I would have taken Derrick Williams. Cavs biggest weakness was at the SF. Cleveland could have also had a great PG in Brandon Knight with the 4th pick. They lost out since they did not get the guy they wanted in Enes Kanter and since they are stucked with a PF who is not that much of a scorer (what they lacked) or shooter. I think it was just greed on their part.