How Nintendo Ruined a Perfect Game

It upsets me when people say Nintendo is for casual gamers. Sure there's kirby and Wii Sports but every so often they'll make a game where the later levels are so tough it makes you wonder whether they're even possible.
Anyone who's played Donkey Kong Country Returns will shudder when I remind them of the giant bat in world 3. Yes THAT FUCKING BAT.
For anyone unfamiliar donkey kong hopped on a rocket barrel that had controls more sensitive than a grabber machine at an arcade. Now imagine trying to manoeuvre the claw of that grabber machine round a narrow path that kept moving while a giant bat spat fire at it from behind, predicting where you'd manoeuvre the claw next.
It was exactly like that. It was satisfying as hell when you eventually did it but it was tough. The thing that kept you going was how you got a little closer each time until eventually you saw the exit of the cave and the bat knocked itself out or something. It was achievable.
A game exists with, what I feel, is a totally unachievable task. It's not a glitch, it's just too hard for my body and mind to cope with. It is one task I've never understood why Nintendo would even include in an otherwise perfect game.
The Boss Rush Galaxy in Mario Galaxy 2.
'Right guys we've almost finished making the game. We only have one level left and it needs to be really difficult'
'We could get all the bosses from Mario Galaxy 1 and put them in the same level Shigeru. That'd be tough?'
'Yeah that sounds horrible! Yeah add that one in on the end. I feel I'm not being the total wank I could be though...how could we make that even harder?'
'Only 3 health points and a 4 minute time limit?'
'Boom'
Why. Why would you put something so stupid at the end of such a great game. No one likes the Firey Dino Pirahna. No one. No one will like it any more if you slap a time limit on the fight with most likely next to no health.
If it was just that by itself it might be ok. You'd die a few times but you could try again right after you failed each time.
Nope, doesn't work like that. Each time it kills you you have to kill all the other pointless mario galaxy bosses again before you get there. It's heart crushing and the sole reason I never finished the game.
I've tried going back to do it but after the second time I just want to throw things at the screen. I'll make it my mission before the end of the year to get that star. I'll just need people to hold me down and being drunk will probably also help.
Nintendo, I like it when you try. But that time you just went too far.