There are two problems, really. One is that this convent really is not in any way equipped to deal with the wave of Cervantes-tourism that is about to descend upon them; and that's not really excusable because this wasn't a case of a child digging under a tree in some rural little backwater town, finding a finger, digging deeper, and discovering that the other arm is missing a hand and the world suddenly descending. The exact grave was unmarked, but we have always known where Cervantes was buried because it was his last wish to be interred in the convent that ransomed him from Algiers. The location and the significance of the find were known before the first spade-full of earth was ever turned.
This was not the hunt for the lost remains of Richard III. That dig was preceded by an impressive amount of investigative work to determine the location of a church that no longer exists, and then followed by hoping that a highly polemical historical record might not lead them astray. In this case, though are talking about a man who died 200 years after Richard III, with legal documentation, and a peacetime burial by allies rather than enemies. There was never any real question that once the archaeologists started pulling up the floor they'd find a one-armed skeleton in a coffin marked "M.C." The scientific institute and the convent should have had a plan in place for the interest that this was going to generate — the interest that they were clearly trying to generate by timing the dig to coincide with the 500th anniversary of the publication of the second part of the Quijote.
Except that in a lot of the really important ways, Madrid is a total, little backwater. In lots of ways it isn't, of course: the Prado, the national library, the great places to eat, the bookstores, the boutiques. But in a certain aspect of peoples' manner and way of being and perspective, Madrid is still proudly the sleepy, uncultured little town it was before the royal court was permanently relocated here in the middle of the sixteenth century; and so why on earth and how, even, would they treat something like this as being of national significance and prepare accordingly? It's proof of Madrid still not seeing itself on the national cultural stage or seeing the broader implications of its own cultural patrimony.
That's where the second problem starts: In sites of cultural patrimony — especially but not exclusively Church-run or -owned ones — people take their jobs and responsibilities not just seriously but really personally. It's their own little fifedom and the resources under their custodianship belong to them and not to researchers or citizens. On the one hand it's great and lovely for a librarian to feel a bit proprietorially in love with his library collection, but on the other, it means that if you come to see something or use it for teaching and research, the response, as often as not, is basically going to be: Get out of my room and stop touching my stuff. It's just the prevailing attitude here.
Mounting a dig for the remains of one of the best and most historically important writers of the modern period and completely neglecting to think ahead to the draw that this will have for readers in Spain and worldwide — or even worse, not caring — is very much trying to have the best of both, selfish worlds: The convent is asking for renewed acclaim for being the burial site of Cervantes while keeping all the acclaimers at an arm's length.
(The right arm.)