Since it's been shown rather conclusively that thinking this team could go on a deep run was a pipe dream, pissing away a 1st round pick for a grade B rental was a really bad gamble. When things go well you get the credit, when they don't you take the blame. And considering how valuable 1st round picks are, Dubas deserves a lot of blame for this one.
If it was up to me, I'd put a hard rule in place right now. Until this team wins at least one playoff round, no more pissing away picks on rentals, period.
Disclaimer - I think rentals are rarely a good idea anyway and saying no rentals never ever no matter what would likely be a good idea as well.