The point that it hasn't been necessary since 10 years has no implication whatsoever for financial stability.
I'm not so sure about that. The Fed having to do this to such an extent suggests a lot of banks are not meeting their fractional reserve requirements. Banks are no long funding their own debts with their own deposits, and instead they are relying on the federal reserve to bail them out on a nightly basis. Something has changed recently (we don't know what) to force the federal reserve to come in with $75 billion on a nightly basis to support the banks.
Banks should be able to support themselves. If they are experiencing daily shortfalls, then it can impact on other lending, which can impact on the entire economy. The Fed having to bail them out like this is a bad sign.
I bet this money printing issue with U.S. has a something to do with countering China's indiscriminate printing of money and has long been accused of currency manipulation by the U.S. Government. I think it has a noble cause.