It's a dumb take.
It's dumb because it makes the assumption that the defense just let some scrub walk all over them. Dude played a hell of a game, and not just him. Their whole offence played like a Super Bowl team. They had a great game plan and executed, all night, for 60 minutes. Yes, I have no doubt the Pats' defense should/would/could have done much better, but the bottom line is, they didn't. They were off balance all game and the Eagles, and Foles, had a little something to do with that.
I realize it's easy to fall into this notion that every win or loss is because of what the Pats did or didn't do, but with any matchup, both teams contribute. This isn't some crappy team that didn't deserve to win. They stepped right up against the Pats and they beat 'em. Straight up, fair game. Foles didn't play like a "backup". He played like an all-pro QB. How he does in the future or how he played in the past don't factor into it. The defense didn't give the game away, they got beat, consistently, for 60 minutes.
Every Pats win has a moment or two of good fortune. That's just how it goes. But we celebrate those wins and our dominance because the Pats were able to hang in there and take advantage of the other team's mistakes. That's exactly what the Eagles did to the Pats. That "backup" didn't make a single mistake for 60 minutes. He threaded needles and executed some ballsy plays when the game was on the line. He wasn't like a deer in the headlights. He didn't look lost or outmatched. He was not a "backup". He was the Super Bowl MVP.