Why can't Jehovah's Witnesses accept being wrong about anything?

The Bible says we are ALL liars. That includes all Jehovah's Witnesses, they are not exempt. Knowing this fact, they have NEVER admitted to having any knowledge about the false prophesies, the documented Wrong dates, the changing doctrines...but every word they utter is Correct, they cannot be wrong...How can a group of men claiming to have Jesus Christ as their leader, be so smug, arrogant, and repulsive. The ones here are the same way. I will admit to making mistakes in my life, and believing things that were wrong, but I also learned how to admit I am wrong, when I am. Why can't they admit the mistakes of their WT, and talk about it? Are they afraid we will make fun of them? No, we would be able to talk Bible with them, and maybe help each other, instead of alienate . Why are you always right JW's? Why can't you admit your mistakes?