Having a privacy feature in Bitcoin will increase government attacks on the sector. It will increase the claim that Bitcoin is used for criminal activities. It could lead to a ban on Bitcoin in some locations like the US. Bitcoin is been integrated into the financial system of the US because the country has developed robust policies and strategies to regulate the industry. The way they are attacking privacy services is the same way they will attack BItcoin if it becomes fully anonymous.
I also agree with you on this, but let's think of it from the perspective of the government, seeing bitcoin as a terrorist tool. It has been long there, and they have been treating it as such, even as they are fighting against privacy tools that are preventing them from tracking down every transaction they want, with or without mixing services that believe the idea they already have about Bitcoin being used for criminal activities can't change easily.
If a privacy protocol can be implemented on Bitcoin, then it's a yes from me, and most people will support that. Even if countries like the US want to kick against it and ban it from being traded by their citizens, it will only be a matter of time before, with growing demand, they will still have no other option than to start accepting it again.