To a certain extent if the lead developer issues a release and says it's critical we have no choice but to trust him. But, outside developers can and should perform their own independent audits of new releases to see if something suspicious is done and raise the alarm if need be.
Most Nxt users are not "developers", so while I take your point, I also suggest that most people are being asked to update software without being able to understand OR verify the reason for the update. It's the software-developer equivalent of "trust me. Just do it."
It's hypocritical to build a decentralized system that is supposed to be trustless, and then ask "untrusted" members of that community to "trust" that they should install new software and not ask questions of the "untrusted" people who issue the order.
You can do your own thing, of course, but I won't give. I'm not gonna jump off a bridge just because Jean-Luc or CfB says so. What they've done is bad, and they should feel bad. When I get an explanation, I'll update my software.
It is unfortunate they had to do it this way, but if they said it was urgent, then it most likely is. The fact that both of them (and I suppose the implicit approval of BCNext) approved it makes it not as bad. C-f-b did say he would disclose what it was, but I'm sure how won't do that until a large majority of nodes have upgraded to 0.6.0.