The Eagles fired Kelly with one week remaining in the regular season. He had a 26-21 record, including 6-9 in 2015, in three seasons with the Eagles after signing a five-year, $32.5 million contract to leave the University of Oregon in 2013.
"I'm a firm believer that bad karma comes back on you," Jackson told Robert Klemko of TheMMQB.com in an article published Friday.
Jackson was released by the Eagles after six seasons in Kelly's first year. Jackson signed with the Redskins and said this past offseason that he felt the Eagles ran a "smear campaign" against him.
"When you ruin a team like that, you do things to peoples' families, you release people, you trade people, you get rid of good players who build something with the community, with the fans, with the kids -- to have a guy come in and change up the team like that, I just believe in karma," Jackson told TheMMQB.com. "I don't have any bad words to say about (Kelly) as far as what he feels he needs on his roster. But the guys that were on that roster created something special, from Jeremy Maclin to LeSean McCoy to Trent Cole to Todd Herremans and myself and Brandon Boykin; it goes on and on and on. When we were there, we were a brotherhood. So for everyone to go their separate ways and to see how it all ended up, it's a very sad thing."
Jackson, 29, is preparing for Sunday's NFC wild-card game against the Green Bay Packers. He has 30 catches for 528 yards and four touchdowns in 10 games this season.
Jackson said he has learned a lot after being cut by the Eagles after the 2013 season when he caught 82 passes for 1,332 yards and nine touchdowns.
"It made me a lot more mature. I got released coming off what I felt was the best year of my career," Jackson said. "I had over 1,100 yards and I still got released? I'm asking myself, 'What was it that I did wrong?'
"But it wasn't about my skills. It was about off the field. But I was never a bad guy. I just needed to tighten up on my end, be more of a professional and know that there was more to it than how you performed.
"Being able to come here and with the kind of success I had in Philly and getting a fresh start was a blessing. I mean, this is a team that I punished for six years straight. I made so many big plays on them, so to come here -- it was open arms. I was happy to be here and they were happy to have me here."