This works precisely as designed. The Hindered effect is not considered a controlling effect. Controlling effects are considered to be effects that cause you to lose control of your character's ability to move - things like Stun, Blind, Immobilize, and Slow. When Electro Net is used on you, notice that Slowed and Hindered are separate effects. You can use Force Barrier while Slowed, but not while Hindered. The Hindered effect allows you to maintain control of your character while active, but it specifically prevents you from using certain escapes such as the ones already listed in Electro Net's tooltip and Force Barrier.
Force Barrier is considered both a defensive cooldown and an escape, since it allows you to completely escape taking damage while it is channeled. If you are Hindered, and find yourself in a situation where you would like to use Force Barrier, then you may use Unbreakable Will/Force of Will to remove the Hindered effect. Then you can activate Force Barrier. Again, I apologize for the poor tooltip descriptions in this regard, as Unbreakable Will/Force of Will tooltips do not state that they remove Hindered (but they do).
While I understand the intent to make Hindered a separate effect from Slowed and other controlling effects (though there is still the begged question of why Hindered isn't a Controlling effect), it seems to still conflict with the tool tip of Force Barrier.
Projects a Force Barrier around you, granting immunity to all control, damage, and negative effects while channeled. This ability does not respect the global cooldown and can be used while controlled.
What kind of effect is Hindered considered? Is it a positive or neutral effect? Or perhaps I should be asking: what is a negative effect?' If Hindered is not considered a negative effect, what is it considered? Perhaps (and I don't mean to sound flippant) these terms could be more precisely defined so confusion isn't created in the future.