Bitcoin is fungible. Like cash, whatever it was used for before you owned it doesn't matter.
The idea of "taint" goes against everything Bitcoin stands for. It's something we need to fight for Bitcoins existence.
Ideally it would be fungible.
Right now some governments are trying their hardest to not have it that way. And are partly succeeding.
If your comment is meant in the way, that blockchain-analytics tools should not be shared, because it goes against the intention of Bitcoin, I have to disagree.
Why? Because any powerful instituation is already capable enough to do these analysis and has all the necessary tools at their disposal. Which means open tools that have similar capabilites will only empower "the people" - they can check any possible leaks / security concerns of their own transactions and take measurements accordingly.
I know you have strong opinions on the topic, but just claiming Bitcoin is fungible when it is clearly not (right now) is imho dangerous. It may lead to Bitcoin-users mistakenly assuming anonymity when it is not necessarily there.