Such as?...
I never saw it as a "loophole", but an exploit, yes.
The difference is enchanting single shield so it's better was easier than creating a wand that would make any shield better for Sun duration, or a shield that would do the same to the bearer (even if he later lost the shield). That makes some sense to me.
It did mean that really large Lesser Enchantments could be pulled off without insurmountable effort, such as huge flying ships (ReTe) or magical traps.
But "magic" is - or should be- an unpredictable thing. There is no way it "should" work, except for game/story balance and enjoyment. 
It is a bit of a headache when something just does not translate from one edition to the next, tho', such as large "self only" enchantments that cannot be replicated.