"Binding"... why not "Bound"?

[Bebekurenai]

It has nothing to do with spiritbond ;;
It's bound to the character after one use, no spiritbond progress at all; a clearer example might be furniture: there is absolutely no spiritbond involved, and as you place one furniture in your house, that piece becomes bound to you.
See the difference in the spelling:

spiritbond -> spiritbonding, as in make a bond between you and the piece of gear until 100%, then it becomes convertible
bound -> binding, as in bound to you because you've used it, therefore not suitable to sell or trade since it's "second hand"

Now read the OP again

[DarkmoonVael]

Items bound to you is connected to the spiritbonding process. There used to be a severe issue with the i70 crafted gear in 2.0 where they wouldnt spiritbond anywhere accept coil, leading to abuse of using them everywhere else then selling them once you got a better upgrade. They would never reach 1% spiritbond level, and would thus never be bound to you. To combat this SE, changed how this worked, and on many things, as soon as you do anything with them, they gain 1% spiritbond, thus becoming bound to you. The spiritbond process is what cause anything to become bound to you at all. Anything glamoured automatically get 1% spiritbonded to you, thus is bound to you. Same applies to furniture.