(That said, and before anyone unfairly cites Godwin's law, I'm of course not saying that the current British government compares in any way to the Nazi dictatorship.)
It's better to stand by your mistakes than to pretend they never happened.
A pardon is a separate and distinct legal action, which is unwarranted.
It's whitewashing because the act of doing it is more offensive than simply leaving it as is. Pardoning Turing would be pardoning him for being gay and makes no correction for the horrendous treatment he received, which was the point of the apology.
An apology is what Turing deserved. A pardon is an insult to his memory.
Same applies to many of those who have been prosecuted under Stalin's rule. Still, there was a process called "political rehabilitation", for lack of better term, which essentially means that their sentences were declared void and their rights were restored. For hundreds of thousands, of course, posthumously.
http://en.wikipedia.org/wiki/Rehabilitation_(Soviet)#In_the_...
Well, Godwin's law be damned, it compares in at least several ways. The Nazi dictatorship was just one of many unjust regimes in the past. No reason why we cannot compare it to others, past or present. They did kill millions of jews, communists, gypsies and gays in concentration camps, but lots of other regimes have killed millions of people too.
Now, as to how the British government compares to the Nazi dictatorship. Well, they have even worse mass surveillance program (CCTV) that the Nazi's had. And the British had invaded and enslaved more countries during their colonial era than Germany ever did. And they are responsible for lots of subsequent wars in their old colonies, since they used "divide and conquer" tactics (establishing artificial buffer states, playing parts of the population against the other, et al) to ensure continued dependance and instability after de-colonizing them (from India-Pakistan, to Israel-Palestine, to Ethiopia-Eritrea, to Cyprus-Turkey, the list goes on).
anyway, the whole concept of law today is based on that idea. law exists at a place, at a time. There are lots of cases that end up like that. "it was NOT a crime then, so even if it is a crime today, we can't do anything".
and on the other way around, by Ex post facto it would be pretty possible to aggravate some other charge based on old laws that applied at the time that today are considered crazy for some reason. It cannot be brought to prosecute gays today just because most countries limit ex post facto for 'rights' acquired later. but for anything else, it's fair game.
crazy.
But the people who say that "anyone who brings up the nazis is wrong" are people pushing a revisionist view of history that denies the holocaust-- because they assert that nazi germany was an aberration, that somehow, magically, has nothing to do with the rest of the world or history, and thus any reference to it is tantamount to simply calling someone a nazi.
As you showed in your post, it is quite possible to make a comparison to Nazi Germany without engaging in name calling, or being irrational.
Thus, Godwins actual law does apply -- you made the reference, and thus Godwin is satisfied (since the likelihood approaches one.)
But the fake "Godwin's law" that people cite is also disproven-- your reference is accurate and astute.