Item Level? I'm not clear

[WindyGamer]

ooooooooooooooookkkkkkkkaaaaaayyyyyyyyy

But none of that appears to answer the question. If you add stuff to the item, or craft a better item, why doesn't the item level just change to reflect the new stats?
If I understand what you've said, the item level is set before we set the stats. Which does not make any sense to me. If you craft HQ gear, or meld something in, then why not just change the item level to match the new stats. But it sounds like we have a "forced error" regarding lack of Elasticity regarding "Melding". So if we make HQ gear, and increase the IL to match, then we can't meld? Well that's easy. "Make it so" Change the item level, but allow enough elasticity in the Melding rules to allow the melding. Geee Are these levels really that close so that the jump to HQ would break melding? And we still want to meld low quality items to that new HQ gear item? I'm surprised that these limits are really so close that moving to HQ prevents a meld you want.

Surely, the devs have a Polynomial [been wanting to use that word all day long, I admit.] relating stats to DPS [Damage Potency] and Healing Potency and therefore to Item Level. AAAAANNNNDDDD I am suggesting that this polynomial which obviously is related to stats, [and quality] and we could easily add melds, should be a monotonic [Another cool word] function related to Item Level. The example above indicates a glitch in that curve relating the two. Let's remove these glitches, shall we?

Right?

[Nezerius]

But none of that appears to answer the question. If you add stuff to the item, or craft a better item, why doesn't the item level just change to reflect the new stats?

Because it would increase the stat caps past the amount that the devs intended for that item.

The item level determines the stat caps on an item. For example, an iLvl 380 crafted healer robe would have a stat cap of 301 crit. The NQ starting at 190 crit, while the HQ version starts at 211 crit.
Increasing the iLvl would also increase the stat cap. The devs intend for a piece of gear to have a specific stat cap.

It's also possible that:
Their system simply isn't able to have two of the same items with the same name, but different iLvls
-and/or-
Their crafting system can't give out one of two different iLvl version during a craft (for example, i380 NQ/i390 HQ from a craft).