(I asked a more verbose version of this question on Sci Fi & Fantasy where it didn't go down well. It seemed to get bogged down in whether or not the Potterverse really is "inconsistent". But I feel it's an interesting topic which might go down better here.)
The Harry Potter books are a ripping yarn, but the logical consistency of their setting tends to play second fiddle to the demands of character and story. It is hard to see how many aspects of Wizard society and economy might function and is the cause of many fan questions.
Of course, there are no rules to say fantasy worlds have to make logical sense. The fashion, since Tolkien, is that they should. But prior to him (and a few later examples), wild flights of fancy were the norm. Kazuro Ishiguro is on record has saying he's not interested in whether his fantasy worlds make any sense, merely in whether they work to help examine his chosen themes.
This makes me wonder whether these omissions may have been partially deliberate on the part of the author. What if Rowling intentionally made aspects of the wizarding world nonsensical in order to make points about modern society?
Take Quidditch. It leaves much to be desired as a sport, yet many Wizards seem oblivious and remain fanatically devoted to it. Could this not be read as a wry commentary on the fanatical devotion shown by many sports fans to what are, after all, relatively inconsequential pursuits? And the "poor" nature of some Wizarding families in spite of the magic available to them. Again, perhaps a comment on how a rich western society still relegates some people to live in poverty, in spite of the wealth of the nation?
Has Rowling ever intimated, or is there any additional evidence, that some or all of the logical inconsistency in her invented world should be read as allegory or metaphor?