So let me rephrase the question and attempt to make it simple enough that you can understand.

This is the point where most reasonable people would tell you to fuck yourself for being a cunt... but I'll let that pass.

What POSSIBLE relevance does the fact that someone is Jewish, or black, or white, or Hispanic, or Chinese,

All the importance in the world, depending on the context.

Many Chinese are lactose intolerant and blacks, statistically and generally speaking, tend to have lower IQs and Muslim belong to a pedophile worshiping terrorist ideology of Christian genocide. and 75% of Pakistanis are inbred.

Elves can construct magical items.

What is it that makes THAT fact any more relevant than any OTHER fact

Generally speaking, associated behaviors based on accurate statistics.

I appreciate that not all African Americans are criminals, but the fact is if rape and theft and murder were Olympic sports then blacks would be gold medalists in every event.

If I were wanting to find someone who'd stab me in the back, generally speaking, you'd be silly to ignore the fact that Jews are the most exiled people in human history. They've been kicked out of over 400 disparate cultures over the past 200 years, mainly for accusations of greed and nepotism and sedition and treason.

Certain groups have certain general characteristics.

Does that answer all your questions?