Solemn vs Gorz or trag or Battle Fader?

can use Solemn Warning on Gorz, Trag and Fader, but you cannot use Solemn Judgment on them?

Solemn Judgment can only negate inherent Special Summons like DAD and Judgment Dragon. Gorz's, ect, Special Summon happens during the resolution of an effect (its own). And since Solemn Judgment cannot be activated in the middle of resolving an effect, it cannot negate Gorz's Special Summon.

Solemn Warning instead can also negate effects that can Special Summon a monster. Gorz's effect Special Summons a monster (itself), so Solemn Warning can negate its effect.
Note that Solemn Judgment can still be activated and negate Gorz's, ect, Normal Summon or Flip Summon.

so which 1 can negate the other?

Warning can negate the EFFECTS that WOULD special summon a monster. Solemn Judgment can NOT negate individual effects, it can only negate the activation or direct summon of a card. Warning can negate Gorz/Trag/Fader, Solemn Judgment cannot.

so thats y ppl dont put judgment inside decks sometimes?

People don't put individual cards in their side or main deck for a large variety of reasons. The main reason why Solemn Judgment isn't seeing so much play right now is because paying 4000 LP is just too much in such a fast paced metagame.