If one of the goals of object orientation is to hide complexity, then tied datatypes are the ultimate objects. Though I agree that overuse of tie might confuse code maintainers, I believe it has a place in more instances than the narrow situation your post defines.

Yes, tie can be used to produce ACMI:: type results, it can also be put to many legitimate uses. If all you need is a variable that acts in a special way, why bother with an unwieldy object interface? Tie is simply one more tool in the toolbelt of Perl programming. Use it where it's convenient and where it provides clarity or simplicity to design.