I went to Auschwitz/Birkenau in 2016. It's place of enormous historical significance. On the same trip I went to see Chernobyl/Pripyat as well, another place of significant historical importance. I don't find anything odd about it at all. It did feel a little weird making decision to go see it, it was a somewhat uncomfortable decision to make, but after being there, I am glad I went. In fact, I think everybody should visit those places. It's part of history, a very somber history, it's part of what happened, what could have happened, and it's a reminder to be eternally vigilant. It is estimated that a million people were murdered at Birkenau. Chernobyl disaster as bad as it was could have been much worse if it wasn't for the sacrifice of thousands of people who effectively signed their own death warrants to prevent a far bigger catastrophe. The abandoned town of Pripyat gives you a glimpse of what could have been, if Chernobyl responders did not stop the reactor from complete meltdown the entire region including Kiev could have ended up like that. A huge portion of Ukraine and Belarus could have been left uninhabitable for pretty much forever.
The two of my biggest impressions from Auschwitz/Birkenau were one, just how big that place was, and the disconnect between the sunny beautiful weather and knowing what took place there. It was a really eerie feeling visiting Auschwitz/Birkenau in the middle of the summer. The sky was mostly blue, the trees were green, birds were singing, the temperature was close to perfect, and you know what, it was really difficult to reconcile the perfect summer day with knowing just how many people were murdered over there. For some reason it really struck a nerve with me. The other thing that left an impression was just how vast the Birkenau camp was. When Nazis abandoned the camp they tried to destroy the evidence by torching the place. 90% of the wooden huts were destroyed with only chimney stacks remaining. And when I arrived over there, all I could see was a sea of chimney stacks stretching all the way to horizon as far as the eye could see. That also left a mark, seeing those stacks of chimneys and knowing that each one of those chimneys represents a hut full of people condemned to die, that feeling is just unimaginable. You just cannot get the same by just looking at pictures, you have to experience it first person.
As far as being disrespectful, to my greatest surprise and disappointment, the only group of people that was actually disrespectful was a group of ethnic Jews tourists. The ones dressed in traditional black clothes, with long beards and curls, wearing traditional kippah hats. It was a really bizarre sight to see. We were given instructions to be quiet and respectful and not to photograph the hair (everything else including shoes, glasses, and travel bags was OK). That ethnic Jews group was the only one who openly disregarded every single instruction. And they did it a lot. Frankly, that ethnic group of jews acted like the place belonged to them, they used loud shouting voices, they pushed other people aside to get a better view/photo, and they were the only people who I noticed to photograph the hair exhibit. I understand that Jews are perhaps the group that was singled out by the Nazis the most, but that was not an excuse to behave like they did.
If you can, you should visit it. Just be respectful for the memory of all the people who died there.