You haven’t yet evidenced point 2 and 3 the cost of De Geas mistakes compared to others costs and also you’re being subjective in your CL assessment as the losses are not his sole responsibility.
Let's put it this way. Fergie famously said (and wrote) that for him, his keepers had to be infallible. They also needed to have the air of infallibility. Take our famous win against Barca in the CL. Would we have that win if Edwin wasn't absolutely perfect? We parked the bus in a way Jose never could against that Barca side and kept out the "best side in the world" for 180 minutes. Yes, our attack against Sevilla and Barca could have done more. At the same time, if DdG had just made that most routine of saves, we'd go past Sevilla and we'd have been level with Barca at a time when we were riding on that "Given Paris, we can expect miracles" mindset. Instead, we were a goal down to a Barca side and then there was only one way we were headed as we could no longer sit deep and hope to keep it tight while hitting them on the break.
Is it his sole responsibility? Of course not! But, and this is the crux, the concessions weren't to great goals. They were because of crap keeping. And that is not good enough irrespective of all else. Should we have retained Alexis, Lingard and the likes as starters just because "our goals conceded were to keeping errors. Keep them out and we'd actually do better"? Nope. The attackers were patently not good enough. We must assess players for each position on their own performances irrespective of performances in other areas. Can't go the way of saying, "Yeah, he's not good enough, but he's not as bad as ..."
Ive never said Henderson has been worse than De Gea this season my point is that it would not be reasonable to say his performance would be easily transferred to United as no GK in PL history has managed this.
Firstly, that's untrue. vdS immediately came in and was great. No random faffing around. He was also our only intra-PL keeper transfer. So, bringing in Dean would make Dean the second and going by your logic of precedent, he should be doing great. (Edwin came from Fulham so again, low-profile club).
Secondly, Dean comes across as extremely confident, knows all that United is about given he's from the Academy and would have to endure an almighty dip to be worse than de Gea has been this season.
I therefore disagree that it would be a great risk.
Thirdly, who then would one get in? Nobody ever? At some stage, one has to say, "This keeper is not cutting it; we need to get in a replacement".
I’m not wedded to my viewpoint. I’m intrigued what do you actually think my viewpoint is?
Quite simply, I think you have - like a lot of our fans - forgotten what we were like. Brutal and ruthless with failure. Aiming for the best and grateful but not beholden to players for their past contributions. We aren't like the obese loser dating a supermodel who will put up with just about anything as long she condescends to date. We're not the reachers in our relationship with de Gea. And replacing him does not mean we do not respect and thank him for his contributions. It's just that as the club moves forward, either players contribute to that process or they get left behind.
Too often, there is the temptation to "stick to the known devil" and also, with de Gea, I presume you're guilty of thinking "he's got his prime years ahead of him". This ignores:
1. Hard data showing a slide
2. The fact that de Gea is more like Rooney - rose early and will fade early given his reliance on specific physical attributes
In summary, I believe you think:
1. De Gea will recover - somehow
2. We should be grateful to him and show it by standing by him
3. Dean Henderson may fail - so why risk it?
Neither of those aligns with how Fergie saw things. And when that's the case, you should know that you're in the wrong.