Tenacious Defense wtf?

Im not sure I understand what this grandmaster trait does exactly. Its seems super weak to me just looking at the description almost a slap in the face. Am I missing something here? Is there some kind of pve use for this or something I admit I only spvp.

It seems to me that they put it in to be a support/defensive ability that players MIGHT use rather than the previous trait that I cant imagine anyone using. Especially running dragonhunter with a shield, Id rather have TD than a trait that boosts ferocity based on toughness when I run no toughness. Guardians aren't asked to tank anything to my knowledge so stacking toughness would have been counter productive to begin with. Personally I like the trait. Based on its wording I would assume it also gets the reduction based on aegis you grant to your party (shield 4 for example) which would be a 5 second cooldown reduction on a short cooldown skill (I solo most of the time so could use confirmation on this). If you dont run shield, fragments of faith etc. then I can see it being underwhelming.

Pairing that with the mantra heal and shield 4 can lead to some very very quick recharge on ToC.