Monero must provide the ability for transparent transactions.
IF NOT then it will never be easily accepted as a transaction medium for important (not casual) payments, for B2B transactions or transactions between the public and the state.
IF i want to pay my dept to the bank with monero I want a transparent transaction!
IF I pay my taxes the same!
IF I run a business and pay my suppliers the same!
IF I buy a house from john doe, the same!
If I pay for subscription to a news paper (online or not), or I pay for my doctor, or I pay for my tickets, or I purchase a gift for me or my family, even If i invest in some stocks or bonds I want noone to know about then I want anonymity!
What are you on about .. ?
This is why we have a view key, which can be used as a simple proof of payment. We've literally mentioned it probably hundreds of times in this thread alone
You have the ability to choose to use multiple wallets, where you can use one to pay taxes, business, buy houses .. etc .. and then share the view key, or at least come up with some form of proof of payment.
You have the ability to choose to use one for your doctor, tickets, gifts etc .. and not share your key.
I think the devs are also working on additional ways to assist you with these efforts, but the point is that what you want is already addressed.