1) Those are major banks. Many thousands of people have accounts with them for 100% legitimate purposes, and most of them have likely not heard that they were involved in money laundering (which, see also #2)

2) Because those are major, highly entrenched banks, they not only have the resources to ensure that stories about them engaging in bad behavior get swept under the rug (which doesn't mean "no coverage", but does mean they don't get covered as much as they might perhaps deserve), they also have the connections to make it very unlikely that they will face any kind of meaningful repercussions for this.

This is quite unfortunate, and a decidedly negative aspect of our current system. But the answer to it is not "so other companies like TornadoCash should be allowed to break the law with impunity, too!" It's "so we need to find ways to change our system so that we can genuinely hold accountable big banks and others who currently break the law with impunity."