Campbell DID have problems in the at least 2 of the 3 playoff games, though I would subscribe that he did fairly well in the Denver game, especially in the 2nd half. However now, according to the current wisdom, his problems have expanded to include the "2nd half of the season", as we enter the free agent season speculations.
The fact is that Campbell rated among the better LT's in the league by all the freakin' charts and graphs we'd get after each game and the various ratings services, right up until the time he was injured at the start of the Bengals game. He did all this DESPITE the fact he was just 21 and not fully grown. DESPITE the fact he was playing next to another rookie LG who was also going through the same rookie mistakes and not a solid vet who could mitigate some of the growing pains. DESPITE the fact he was thrown into a brand new complex offense, new language, new coaches, etc, etc. DESPITE the fact we have no idea how much of his issues during the playoffs come because of his serious knee injury.
We almost hear NOTHING about that. I did see one analyst (an X-OLman) state that he was getting to his 'spot' well enough on his drops, but too often didn't have the balance and control to anchor and stop the defender's initial progress. And it wasn't like he could NEVER do it, he just didn't do enough. Now how much of that issue was because of the injury, I have no idea, but I'm sure it didn't help.
The fact that PATRIOT fans are calling for Campbell's move to LG, or RT, or anywhere else just boggles my mind. Myself I'm more of the mind of going to get a quality veteran FA LG to be our version of the Bear's Joe Thurney pick up. Someone like Seimalo, Edwards, or Bitonio, and them move Wilson back to C and save Bradbury's cap space. (though I wouldn't hate it if Bradbury was back and some other iteration of OL remains. He was more than often very solid all year and better than I was led to believe.)