The short answer is "no, I do not believe that a perfect deity would create imperfectly."
For the long answer, I think it would be useful to clarify the standards for perfection. For example, how would you answer, "What is a perfect deity like?"
I think part of the question of "why would God create this?" depends upon how you describe a perfect God. That would, in turn, describe a perfect creation and whether it had a purpose.
Of course, it would probably be advisable to define "God." The question, as it was posed, asked about "a perfect deity," which is by definition God, since there can only be one "perfect deity."
When the question was originally posed, it seemed to me to presuppose that existence is flawed and has been from day one. If God does exist, then creation would be perfect, since a perfect deity that messes up is, well, no longer perfect, thus not the Sovereign God. An imperfect deity is merely a very powerful being, not the All-Powerful Being. If the question were posed as an argument, one could argue that since creation is not perfect, God does not exist.
A perfect deity could easily a world where everybody did exactly as they were told and never stepped out of line, where volition was suppressed, if not altogether absent. But a deity that creates only robots would not be as perfect as a deity that creates free creatures, right? And it seems clear that we have free will.
By what standard are we measuring perfection? Is a perfect life where there are no traffic jams, no "common cold" or toothaches, where nothing unpleasant, let along bad, ever happens? Is such a world possible with human free will?
I can't keep going on like this, so I'll summarize as follows:
God is perfect, so creation would have originated in a state of perfection, populated by free moral agents, orpersons. The presence of free will means potential (and actual) corruption of that perfection. Yet a perfect God would correct that corruption, thus allowing free creatures to voluntarily live free of corruption in harmony with God and others.Whew!! Get all that?