How come I can't need upgrades ?

Simply, Cyklon, because restrictions had to be placed on the Need before Greed looting option to make it viable for the Dungeon Finder Tool and those were the changes that were agreed upon by our Developers.

Are there items that may be an upgrade for you that will drop? Probably. As stated though there are also leather items that may be a better upgrade to the cloth that dropped. We want those classes that use only cloth to be able to acquire those items and not have to compete with other classes. Just like we want leather wearers to acquire gear that is best for them.

Imaging this scenario: If you had been able to need for the cloth, theoretically beating a cloth wearer for the item and then a leather item dropped for that slot that was better than what you just acquired you could need for that. If there were no other leather wearers in group, you would easily be able to get the item.

Technically speaking since the cloth item was yours you wouldn't have to trade it to another cloth wearer in the group. This means that the cloth wearer lost out on an item that would have been better suited for them simply because you "could" use it.

That is not how we currently see this option functioning.

http://us.blizzard.com/support/article.xml?locale=en_US&articleId=30305

You may always talk to your group and if they agree they may allow you to have an item that you are unable to need on.

If you feel that any changes need to be made to the looting system you are welcome to post in the Suggestion forum. Our developers and policy makers read that forum frequently, and take into consideration all suggestions, even if they are unable to directly reply to them.

Q u o t e:
Why not make the greed roll top the DE roll then?

Most shards sell for way more on the AH then those drops do to a vendor, so that isn't a good reasoning behind not allowing it.

Most, not all, and the market is always subject to change. An arbitrary price based on a realms economics wouldn't necessarily be the deciding factor in a decision.

A greed roll means just that, you are taking it for it's value. Be that a vendor value or a market price value for the enchanting materials.

One thing to keep in mind, folks, the suggestion forum is your only method of providing feedback regarding these systems. I can try and explain why a certain mechanic may have been implemented in its current form but I'm not a developer nor are we liaisons with Development. Many of you are looking for a dialog, all I can give you is possible reasons based on a logical assessment.

Thank you all and have a great night.