Harry Maguire is a player with nerves of steel, as there was a time when he played terribly and underperformed , but that didn’t discourage him or make him run away from his place. Even though at that time he received ridicule from anyone who wanted him to leave and he even had to take off the captain's armband that he wore, but none of that dampened his spirits and what makes me respect him is that he still loves Man United , after all that treatment. His patience has now paid off, as he is now performing so impressively and making Man United’s defence look solid . So it makes perfect sense for Man United to offer him another contract because he still makes a significant contribution.
What else was he suppose to do, retire? I mean dude was contracted at a team that he played awful for and people hated him and even mocked him and he was a meme, and while that has not been the case this season so far, it's clear that he is still subpar to United level and not a defender for a top three team.
But when all was going bad, he was still contracted to the team, so unless he retires, there was nothing he could do but just keep doing his job. Do you just retire when you make a mistake at your job? I make mistakes too, I am sure I have, and yet in the end I keep working like nothing happened because there is literally no other option. You try to be more careful of course, but that's about it, you just have to keep going.