A fully geared pally with all +10 gears can barely make 100def. And, even if you could get 120, it would be useless, because you will already be taking 0-1% dmg.
That isn't exactly true. I'm using quite a bit of +7's and such, and manage 102 DEF. If I had all +10 gear, I probably wouldn't have 120, lol.. but I dunno.. maybe 112~15'ish.
Also for not getting hit at all. That also isn't true. DEF doesn't block skills too much, if at all. It can water down the damage significantly for sure, but usually never entirely. DG is a good example of that. It's also more than 1%, Valkyries are proof enough. Keep in mind as well that the more on you, the more your total DEF is falling too. So having more is still always a good thing. (Just highly unlikely to obtain the gears to keep doing so after a certain point, due to too much difficulty/money)
With your mindset though, I could simply walk up to an MVP and never get hit with a Physical Melee Attack, due to having a lot of DEF. Not going to happen my friend. :<