Yes this is actually the weakness of Javazon in general, casters like QT and Sam and Scosglen Boss and Deimoss. No blocking, no defense, and this is part of the defensive concept of the build with is unique.
and, to make this more of a point, exactly this is the strength of Assassin defenses, casters. So a comparison is difficult, because they work quite different.
That does not, indeed, make the point of "it would be nice if poison Java would be able to do endgame stuff" invalid. But what i don't like is the idea of "every poison build should have the exact same power level" because, following that logic, every melee build should have the exact same power level etc., which is a ridiculously difficult task to accomplish for people who do this for fun in the end.
As QT is a midgame boss, have you tried to use little helpful things like
Aerin Orbiter
Aerin Orbiter
Belt (4)
Defense: (88 - 96) to (121 - 132)
Required Level: 5
Required Strength: 28
Item Level: 10
5% Cast Speed
+(4 to 5)% to Fire Spell Damage
+(4 to 5)% to Lightning Spell Damage
+(4 to 5)% to Cold Spell Damage
+(18 to 29)% Enhanced Defense
+(11 to 15) to Energy
Elemental Resists +(3 to 5)%
Elemental/Magic Damage Reduced by (3 to 5)
Socketed (1)
Defense: (310 - 334) to (389 - 419)
Required Level: 22
Required Strength: 56
Item Level: 31
15% Cast Speed
+(8 to 9)% to Fire Spell Damage
+(8 to 9)% to Lightning Spell Damage
+(8 to 9)% to Cold Spell Damage
+(41 to 52)% Enhanced Defense
+(21 to 25) to Energy
Elemental Resists +(9 to 11)%
Elemental/Magic Damage Reduced by (9 to 11)
Socketed (2)
Defense: (754 - 805) to (938 - 1001)
Required Level: 40
Required Strength: 201
Item Level: 51
25% Cast Speed
+(12 to 13)% to Fire Spell Damage
+(12 to 13)% to Lightning Spell Damage
+(12 to 13)% to Cold Spell Damage
+(64 to 75)% Enhanced Defense
+(31 to 35) to Energy
Elemental Resists +(15 to 17)%
Elemental/Magic Damage Reduced by (15 to 17)
Socketed (2)
Defense: (1104 - 1173) to (1358 - 1443)
Required Level: 48
Required Strength: 402
Item Level: 77
30% Cast Speed
+(14 to 15)% to Fire Spell Damage
+(14 to 15)% to Lightning Spell Damage
+(14 to 15)% to Cold Spell Damage
+(75 to 86)% Enhanced Defense
+(36 to 40) to Energy
Elemental Resists +(18 to 20)%
Elemental/Magic Damage Reduced by (18 to 20)
Socketed (2)
and
Wheel of Fortune
Wheel of Fortune
Large Shield (4)
Defense: 85 to 162
Chance to Block: Class%
Required Level: 4
Required Strength: 27
Required Dexterity: 45
Item Level: 10
+(21 to 30) to Vitality
Maximum Elemental Resists +1%
Elemental Resists +(6 to 10)%
Fire Absorb 1%
Lightning Absorb 1%
Cold Absorb 1%
(4 to 7)% Gold Find
(5 to 10)% Magic Find
Socketed (1)
Defense: 240 to 405
Chance to Block: Class%
Required Level: 21
Required Strength: 53
Required Dexterity: 67
Item Level: 31
+(31 to 40) to Vitality
Maximum Elemental Resists +1%
Elemental Resists +(11 to 20)%
Fire Absorb 2%
Lightning Absorb 2%
Cold Absorb 2%
(9 to 12)% Gold Find
(11 to 20)% Magic Find
Socketed (3)
Defense: 501 to 817
Chance to Block: Class%
Required Level: 39
Required Strength: 184
Required Dexterity: 139
Item Level: 51
+(41 to 50) to Vitality
Maximum Elemental Resists +2%
Elemental Resists +(21 to 30)%
Fire Absorb 2%
Lightning Absorb 2%
Cold Absorb 2%
(14 to 17)% Gold Find
(21 to 30)% Magic Find
Socketed (4)
Defense: 684 to 1113
Chance to Block: Class%
Required Level: 48
Required Strength: 368
Required Dexterity: 288
Item Level: 77
+(51 to 60) to Vitality
Maximum Elemental Resists +2%
Elemental Resists +(31 to 40)%
Fire Absorb 3%
Lightning Absorb 3%
Cold Absorb 3%
(17 to 19)% Gold Find
(31 to 40)% Magic Find
Socketed (4)
to increase your elemental defenses? also, overcapping res (by 20%) might help against mythal, and melee range (as op stated) gives you additional protection to apply strong poison from impale.