I think the biggest reason is that Bitcoin values first the ability to verify all transactions athat occur on chain.

If you want to verify every transaction, you have to know everything about them. That means you have to know where the bitcoin came from and where it's going. If I didn't know this, I couldn't verify the rules of the network, so there has to be a large trade-off of reduced privacy to provide the clarity needed for everyone to accept valid transactions.

Knowing this, people who want privacy have to come up with clever ways of "hiding in plain sight" to cover up their on-chain activities. Since it's difficult, a lot of people bitch about it, as if being private in other areas of life is any easier. Try maintaining your privacy online or even in your day to day life. You'll find it's hard and requires a lot of discipline. So why should Bitcoin be any different?