Yes, adults going to WDW, especially alone, is weird (I have heard a single justification that shamed me a little, but for the most part, it's weird). Let me toss in right quick, I do weird stuff too. I go to Comic cons alone, and that too is weird. Again, just own it. People cannot seem to do that anymore. I blame the social justice movement. Nothing is abnormal, everything should be embraced. ...so long as it doesn't hurt anybody. And they mean anybody. Except maybe republicans.
People also cannot seem to understand probability and percentages. In a world of grey, this is a hugely beneficial ability. Some of these are very simple observations. Look around WDW when you are there, and draw some easy basic conclusions. Look at the adult to child rations. Look at the age demographics. Observe the solo adult levels and quick compare it to the solo child levels (the latter always correlated to the prior). It's not rocket science to discern what is normal and what is abnormal. Rookie mistake: assuming you are normal. Or average. Whatever word you what to use here. You have to look at other to determine normal. Normal can change over time btw, what is normal 50 years ago may not be today.
Huge sidetrack, my kids school has a furry movement going on. Young adults want to wear giant furry costumes and have it accepted as normal and accepted. Sorry, but it is just weird. No matter how progressive I want to be, it is super weird. Weirder even than solo adults at WDW. * oh no he didn't*