Perhaps adding the ability to control the number of revisions stored via the wp-config.php file would be a good compromise?

Adding it as a core feature in the admin panel seems a little overkill. But adding a simple line in the wp-config.php file which could be uncommented when necesary seems fairly reasonable to me. Controlling how often the revisions are stored is not as useful IMO as controlling the number of revisions but at least it offers some control to prevent the database size exploding.