Don't want to derail the Aiyuk thread but I'll answer these questions:
Who exactly are the people "Shaking their heads" at Devonta's deal?
Off the top of my head, me, Joe Banner, Randy Mueller, a few beat writers I follow including whichever one asked him if he already regrets taking that deal. And I'd assume most of his dynasty owners. Great deal for the Eagles. To be clear the people shaking their heads is because he took the long term security but failed to maximize his overall pay and then saw his own team pay another WR on the team way more then him.
There is a reason Aiyuk has reportedly already turned down getting paid MORE then Devonta was offered. It's just not a great deal, just especially worse when you consider the pecking order it put him on his own team, and he's not exactly got Kyle Shanahan dialing things up for him.
You "really hate" he's put himself in what situation exactly?
Kind of said it already but I will again. I think he's better then to put himself in a position where the team values another WR on the team $7M more a year then him. Just think he's better then that. I feel like he's a bona fide #1 WR who will spend the entirety of the prime of his career being paid and treated like the #2 WR on his own team. And with a QB who I still think has limitations as a passer. I would have liked to see him have more "dog" in him. To think of himself as his team #1 and want to be paid and treated that way. He accepted being the second banana on his own team, and by most account has already taken a contract that looks under valued. You can throw around long term security but he'd have had that and more pay, and a higher standing in his teams pecking order, if he had not agreed to an extension so early. Secondly his legacy. If he wins a SB, sure that help a lot but his stats will likely never be huge, decent but not huge, people will continue to debate if he's just a good #2 and not a #1 and because he's wrapped up till his age 30 season these are answers we may never know.