Well, since you asked the following guys have had better years playing with someone else other than playing with Newton:
Brandon LeFell
Louis Murphy
Jerricho Cotchery
Ed Dickson
Russell Shepard
Torrey Smith
Jarius Wright
I mean, you are looking at a QB who has a career sub-60% completion percentage despite starting for 8 years in the league. That’s hardly a ringing endorsement in a league slanted dramatically towards the passing game. I’m not sure why it’s “hate” when people point out the obvious flaws in Newton’s ability as a passer.
Newton has flaws but I don't see where his flaws have ever limited his receiving options from reaching their fantasy potential. Also completion % is only one stat- Sam Bradford can complete 75% of his 5 yard check downs but that never made him any good in real life or fantasy. Cam is 12th active in yards per attempt and 2nd in yards per completion so part of the reason is completion % is lower is because he throws down field.
Anyway, lets look at the list of WRs who did not reach their potential because of Cam:
- Lafell: With Cam he had a 16 game average of 667/4, with Brady/Dalton it was 780/4. Not a huge difference- especially if we consider Cam was a rookie and Lafell was a 2nd year player for one of the 3 Carolina years. Lafell had a whole season with Brady where he didn't score a single TD.
-Louis Murphy: He spent 1 year in Carolina where he started 5 games and had 336/1. After that he averaged 310/2 over the rest of his career. I don't think Murphy was very good.
- Cotchery: Spent the final 2 seasons of his career in Carolina and at ages 32-33. He averaged 588/2 which was right in line with his previous 4 years in Pittsburgh/NY where he averaged 415/4.
- Ed Dickson: In Baltimore he was average 314/2 and on Carolina opposite a Pro Bowl TE he averaged 202/1.
- Russel Shepard: We will ignore the first 3 years of his career in Tampa when he never played. His last 2 years in Tampa he averaged 219/2. His 1 year with Cam was 202/1.
-Torrey Smith: Yeah he was bad this year. He has gotten worse year after year, but sure lets say Cam really messed up the season people were hoping from Torrey Smith in 2018.
- Jarius Wright: 413/2 average in Minnesota. 447/1 in Carolina.
I am sorry but I think you just listed a bunch of players who were either never good or were at the the end of their careers.