Mark -
I'm not at all against renovations, including the (preferably sympathetic) renovations of old classic courses. As Mike Y says, members get to choose, and there are many practical and legitimate and understandable reasons for clubs (and their consulting architects) to opt for renovations.
But the purist in me rebels against the misuse of language in this regard: I think we all know exactly what a "restoration" means/entails -- even if there are many reasons for members & critics & architects to want to obfuscate/blur that definition.
Example: a 1920s course was originally 6350 yards long, with two sets of tees, and fairway bunkers some 200-225 yards off the tee, with very few trees, and large & well-contoured greens with slopes sometimes in the 3-4 degree range, and deep green-side hazards set hard against the edges.
A restoration would result in a course that is 6350 yards long, with two sets of tees and fairway bunkers some 200-225 off the tee, with very few trees and well-contoured & sloping greens with penal hazards set right up against them.
That's a restoration. Everything else is a renovation.
Now, as Joe H has just pointed out: such a true restoration doesn't mean that we today will be playing the course the same way they did 100 years ago; but it does mean that the course itself will exist in the same way it originally did.
Again, I'm not making a value judgement here: if a decision is made not to honour/realize the course as it originally existed but instead to have it look and play very much like it might have a century ago, that's fine. But then it's not a restoration.
As I say: I think we all know what that word actually means.