Revisions in WordPress are all about editing power & recoverability, but excessive use comes at a price (call me performance penalty).

Studying the pros and cons of revisions, we have decided to enable revision control for all of our customers, with a predefined value of 5 revisions (excluding the auto-save feature).

You need more revisions? Given that you actually have a solid use-case, you can always reach out to our support team and we'll be more than happy to help you out.