Again, it feels like you are looking at the situation now and not then, when the Packers had to make their decision not to give Heyward the kind of money that the Chargers did. I would imagine if the Packers felt Hayward's services and the money he was commanding was worth it at the time, they would have kept him. Based on fan reaction to the money paid to Jones, Perry and Starks on their resignings, as well as most of the comments on why letting Hayward walk was fine, had TT matched the Chargers offer, there would have been grumbling over that as well.
Sure if you could use hindsight and plug in the stats Hayward has this year, he would have been an excellent resign. However, had he gotten injured or played similar to his other 4 years in GB, not so much.
Another way to look at it, if you were TT and you could resign Hayward this offseason, would you pay him the kind of money his stats are reflecting this year?