Basically by using the item's caster level as a pre-req for the crafter's caster level, you break all sorts of things within the campaign that later then have to be fixed.
The DMG is really quite clear but often people misunderstand about crafting and what is required. The requirements are listed under every magic item and the 'caster level' of the item has nothing to do with it.
What you need to do is meet the requirements listed, have the time and cash on hand (and XP) to make the item and be able to cast (or have an NPC cast) the spells listed. There are a few other exceptions that deal with enhancement bonuses (and levels required) to do armors and weapons but again the DMG explains what these are.
An example: Pearl of power. (listed as caster level 17 for the ITEM) The requirement is have craft wondrous item and be able to actually cast spells of the given level of the pearl. That's it.
Exception being for example the ioun stone, which the DMG specifically states requires the feats necessary and being a 12th level caster.
LG originally used this system to 'control' magic item creation and it ended up just being a nightmare. (with all sorts of things that had to then be modified or they made no sense)
Like Sovereign glue? Caster level 20?
I'm all for 'fixing' magic item creation to be something more reasonable, but the way Pathfinder is suggesting to do it, causes more problems than it fixes. (lots of headaches)