No, of course not.
More specifically, it depends on which Enclave you're talking about: the one in Fallout 3, or the original.
Even then, the answer is still 'no'. This is a world of gray and gray morality, remember: no organization is purely good or purely evil.
And it is evolving- for a good example of how the Enclave has changed from what it was originally, look at the dichotomy of President Eden, who represents the 'old' Enclave, and Colonel Autumn, who represents the 'new'.
I
will give you that the original organization was made up of a bunch of right [censored]s, interspersed with a few bright rays of hope. >.>
Originally, the Enclave was out to preserve itself and everyone else = pretty much screwed.
As stated above, the "new" Enclave -or at least, the human face of it- seems to think this is extremist bullcrap. (To wit, Autumn's outright refusal to
Spoiler insert FEV into Project Purity.
)
Ah damn. I'm making a hash of my explanations again, aren't I?
Eloquence, why hast thou forsaken meeeee? ;3;