The items to bump UMD that high - like the 7-Fingered Gloves - are either raid gear, shroud items (CHA skill) or otherwise named and have usually a ML. Being able to have something like 'Skill: Improved UMD' which even not take a slot of any gear, would make it available for a lot more players without the need to grind those items. But UMD is a too powerfull skill to give it away that easy, making it easy to buff you, use wands, heal and rez scrolls along with all items that need you to overcome a restriction (why needing a healer or caster anymore?).
Also keep in mind that +5 UMD on an item is equivalent with 10 skill points in UMD for every character other then a rogue. Which means factoring this into your build plan you could use those 10 points on other skills like balance, intimidate or whatever instead putting them in UMD. Not to mention that base skills and enhancements would stack with items.
Players who say it is easy to gain +44 UMD play probably since quite a while and have those items, but the majority of the casual player have not, but as it is possible to reach those values I not see the reason to dump down that game any further.
just my 2 cents