There is no such thing as a "TRUE" steel wheel unless you just happen to luck out. The center part is welded to the outer part in a jig and there is just no way it can be true every time it is welded. The aluminum wheels are cast as a complete wheel then spun and cut on a lathe and are true.
If the tire is way off on balance on a steel wheel then turning it on the rim by 180* may correct it and the tire is within spec and it is the steel wheel that is not true. There is actually a machine made that you put the tire and wheel on it it monitors the tire and the rim for trueness then tells the operator where to mount the tire to get the whole setup as true as it can be.
I do agree that if the tire will not balance within a set amount of weights on an aluminum wheel then it is out of spec and another tire should be installed but not always true on a steel wheel.
"Gunner" USN Retired, Airdale
2004 Monaco Signature 44' Conquest. Detroit 60