Why? It's not the "base model" it's the lowest capacity of the absolute highest end phone in the lineup, which now comprises five different phones at much more reasonable price points.
So your argument is basically that no phone should be that expensive? I can't speak for anyone else but I hate that. What is wrong with a super-premium phone? If anything phones are frustratingly constrained by their price point.
People use them in the way they used laptops 10 years ago, they're your central communication hub and for many people their secondary or even primary computer. What's wrong with having a high end option for those that use their phone more than everything else.
I'm buying the iPhone X day one. Why wouldn't I? I haven't upgraded my desktop, laptop, gaming PC, tablet, or smartwatch in 2-4 years, but that's because I don't use any of those things even close to as much as I use my phone.
If I'm spending multiple hours a day every day using something, you'd better believe it should be the best one available. If you don't feel that way, there are four other iPhone options and countless Android options at your disposal.