Yes, they essentially completely useless, you can acquire better blues that will last a longer range of levels from the GTN.
If they actually scaled with your character, or provided an exp buff or something, then they would be useful. As it stands now they are basically a fluff item you can use for two levels and then bank, or not use at all if you actually want to have a good weapon.
PS: People need to read the mail lol, seriously, you just unattach the item and go on your way without even bothering to read the attached instructions? Reading half a paragraph is serious business, on noes!!!!!