Eh, it's going to depend on a lot of different factors. A masquerade pretty much can't work without some level of magic, super tech, or reality bending bullshit to stop people from eventually finding out anyway. With 7-8 billion humans on the planet, unless this society is completely separate from humanity, as well as self-sufficient, then they would have needed some kind of mechanism to not be discovered already.
This kind of already puts them on shaky moral ground. Vampires like the Twilight and VTM style usually do it through copious amounts of murder, blackmail, mind control, and some stupid bullshit ability that lets the VTM vamps automatically screw up cameras without thinking about it. The Harry Potter wizards do it through, lots and lots of mind control and memory editing.
In either, case it would be hard for me to be able to morally justify keeping the masquerade while still attempting to achieve any moral high ground. It is kind of hilarious that so many people are bringing up humanity's penchant for judging groups different from us, and then talking about secret society's like Harry Potter and VTM, where humanity would have a very reasonable and extremely justified reason for being pissed at and scared of the society being hidden. In vampires case, yeah humanity kind of has a right to be pissed at a secret society that casually treats humans like cattle and slaughters them on a whim, accepting gay people as equal citizens is a little different from accepting Count dipshit who was complicit in hiding his mass murdering fuckwit friends from society at large. The Harry Potter style wizards aren't much better, even the good wizards like to casually brain fuck anyone who gets close to them and treat non-magical people more like pets than actual thinking people with rights, the evil ones just kill and torture non-magical humans for giggles and shits. On top of all that, both of these societies are basically parasites on human society at large, taking resources from governments and people and generally contributing nothing in return. In those cases, I would probably try and blow the masquerade wide open, if it was feasible; I probably wouldn't bother if there was some bullshit reality warping that was preventing any humans from finding out, because then it would be pretty pointless.
In a case where the secret society actually was just living totally separate from humans, not being parasites on larger society, and just wanted to live on their own due to fear or some other somewhat benign reason. Then yeah, I could probably keep the secret then, it would make me uncomfortable, and I would probably feel like I was betraying humanity, but if these supernatural creatures, wizards, or aliens, or whatever can actually convince me that the masquerade is a necessary precaution, then I could maybe be persuaded to do my best to keep it up. It's really going to depend on the circumstances.