But mostly bad. People paying for good (or more specifically, something generally popular) don't need to hide what they're doing, as a general rule.
Is there numbers on this? Because of how "dark money" is defined (ie. any sort of 501(c) nonprofit), technically any 501(c) charity (eg. even something like NAACP) is "dark money".
People can be wrong and later realize their mistake, it's not something we think about when supporting a cause; how will I be viewed in the future for this? Maybe we should.. Until then, anonymity in donating allows someone to express their opinions as they see the mores of the day to be, now, without fear of retribution, and protected for the distant future when they've realized how wrong they were and changed.