You're not wrong. But would you rather spend your Bitcoin on merchant who discriminate incoming Bitcoin (usually also with little explanation/transparency) or merchant who doesn't do that?
I get your point, so my answer is that, as long as they accept it, I don't care if they discriminate my coins.
But if they don't accept it, then yes, I 'd rather choose merchants that do. In fact, I am obliged to do so.
The thing is, if merchants choose to believe what the governments say and start filtering coins, then we 've lost. All of us.
Let's say you've been earning coins from signature campaigns for years and now these amounts are on the 6 figures and you want to spend some of it in things because otherwise is just an useless number on a screen.
The moment you want to spend these coins, you have a problem if some of them are blacklisted in some of these chain analysis software, and most services have or will have these services in place by law eventually, which means you have all that money stuck doing nothing, unless you want to spend it on cheap stuff and only on p2p purchases basically. So this limits all that money to basically irrelevance since most people already has fiat to spend on these small purchases and paying with a bill is easier and more private than having your transaction in a blockchain record for life.
So the point here is, it doesn't matter what you believe or don't. The moment your coins enter in contact with those chain analysis software and you are unlucky to be holding some of them and they know who you are, you have a problem. You can believe taxes are theft, or that these blacklisting softwares are bullshit and unfair which I agree, but that doesn't matter because the consequences are not desirable, so you want to be aware of these things. As it stands Bitcoin implies this risk when paying for things. Yes you also have the risk of owning counterfeit fake bills, but when you pay it doesn't get automatically analysis through a permanent database.