Okeydokey. FWIW, I agree that higher-level minions are an entirely new thing in 4e. I think they're a
good entirely new thing, and don't hinder the kind of world-building I do (which is all very high-level and abstract, rather than detailed), but they're definitely new.
And because they're new, there's a tendency to treat them like things in previous editions. You
can't, though - at least not without getting silly results. Stuff like commoners with rocks vs. level 29 legion devils, or (in the PC realm of things) a Cloud of Daggers from a level 1 wizard auto-killing a that same legion devil... well, they break the minion system. I don't think that's how they should be used, and I know they will turn out silly, so my choice as a DM is
never to do that. 
It's like throwing my computer out a window - while it might be tempting to try, and it occasionally sounds interesting, I know it can't end well.
Minions require a subtly different way of dealing with creatures. If you think treating a creature as a minion would do something insane to the system, my suggestion is that you don't do it. Use common sense and only use minions when they seem like they would be fun, or else add something to a fight.