Its obvious from my post history what I think of De Gea but I want to stress that this is about more than just an individual player.
Since SAF, the club have handed out ridiculously oversized contracts to underperforming players. That's problem number one, and it applies here.
The second problem is that players have started to dictate to US how long they stay at the club. In SAFs time, he was famously outstanding at identifying when the time was right to move a player on. Lest we forget, he teed up the sale of Rooney for Moyes, but Moyes made a huge blunder and handed him a new long term contract. De Gea would have been gone 3/4 seasons ago under peak SAF, I have no doubt about that.
Third, we need to get away from this habit of collecting footballers who are not good enough and giving them multiple opportunities to fail. How long do we think the likes of DvdB, Fred and Martial would have lasted under SAF? Famous flops like Djemba Djemba, Kleberson, Bellion, Obertan, Bebe etc...barely made it to 20 starts. The likes of Fred have been allowed to fail over and over again, prolonging their career with one good game in five convincing the club that they can serve as "depth"....its rubbish. If they are not good enough, get them out. Even if that leaves you a bit short. It needs to be done.
When SAF decided that time was up for Kanchelskis, Hughes and Ince he got rid. He didnt think "well, actually, Kanchelskis could be a useful option off the bench with his pace...". He saw his head had been turned, he saw his performances had suffered...bang...you're out.
For me, what we do with DDG will come to define whether we/ETH have the appetite for real change or simply a facelift. DDG needs to leave. I dont care if he offers to stay and play for free. Sorry, you have to earn the right to play for United in every single minute that you wear the shirt....and he has lost that right with his performances over the last few seasons.