Is the context totally lost on you? "...that if the British Empire exist for ten thousand years, men will still say 'This was their finest hour!'" So either Churchill isn't great at English or he's talking about the Brits.
What Churchill meant was that it was the ENEMY'S finest hour even if the Brits exist for a 1000 years. Tell me how it was Britain's finest hour when they just lost France and was about to come under attack from the same foe that had crushed half of Europe and I'll believe you.
Have you ever heard the phrase "Winning isn't everything?"
Churchill was basically stating that whether or not the British prevailed or not, they ought to put up one hell of a fight. Not because they would necessarily win if they did so, but because there was some inherent value in putting up that fight, and in putting up the best fight possible, and even if they did prevail, they would be remembered for 1000 years for their courage, bravery, and devotion to duty.
Britain, at that time, had watched a number of defeats and I'm not sure if the US had even entered the war yet. So they were facing interminable odds. If Churchill had gone on about actually winning the war, they probably would've thought he had lost his mind (I don't think anybody was that good of a speaker - they'd be twisting reality.) So instead he chose to praise the act rather than the achievement. It's like if you win the race, and you get praised for doing your best. There are sound reasons for that, of course - if you consistently try, you're more likely to do better than someone who slacks off and does a half-assed job. But overall, a lot of people truly think that there is some abstract value in simply putting up a fight or going into something with your entire heart, and that's what Churchill's playing to.
Putting that into the current context, the Colossus was also facing interminable odds. There was clearly no way it could win against the Sathanas. Yet rather than turn tail and flee and desert its post, it chose to go down fighting. Granted, in the context of the mission, it's arguable whether that was truly the best thing to do. But at that point you have 30,000 people sacrificing their lives to at least try to simply buy some time. If that doesn't qualify as attempted heroism, I don't know what does.
That mission is also the last mission where the GTVA engages multiple capships, up to a destroyer, in a straight-out fight and comes out victorious in many cases. The total number of capships destroyed is probably greater than virtually all of the missions in the campaign, save for the blockade one. It's only the Sathanas, which the GTVA had no way of destroying short of a planned surgical op, that wastes the fleet at the jump node. So truly, even though the GTVA force at the node was eliminated, they still did a better job than most of the forces that you saw in the rest of the campaign had, at least in terms of causing Shivan casualties.
I really don't know why people have such a hard time understanding this. There are a lot of TV shows and programmes and movies that outright praise bravery and heroism over the enemy that has the technological advantage and superior forces et cetera. Granted they usually win, but a lot of times they are forced into a situation (much like the GTVA) where they seem to lose, winning is untenable, and they have a small moment of quiet, and then somehow pull a victory out of their ass that they could have only made with the sacrifice of some force in a great battle. There's no reason to expect that the GTVA wouldn't have done something like that, given that it's exactly what happened in FS1.
So overall, I think that both the Churchill quote and the mission name both have the same thing in common, they're praising an act of heroism in a time of almost certain defeat. It's not meant to be ironic in any way.
Or, let me put it in yet another way - how do you motivate someone to fight when they know they're going to die?
