Hyperbole aside, I think corruption should (be removed, but barring that) act like a titanforged (+10 to 15ilvl max) item that begins with the bonus exactly balanced by “corruption” which acts like negative stats. This way it will always be equivalent to an uncorrupted piece initially, but you can unlock the full power of the item as you earn corruption resistance or whatever.
I.e. like the valor upgrade system that people actually liked in practice, but thematically appropriate for this corruption thing the devs are excited about.