"We were up against a very strong team/driver combination, one of the strongest we’ve seen so far, but our goal was to be stronger than that and in this regard, we failed," said Vettel, who has since joined Aston Martin.
"We had good races, bad races, we got close, sometimes far away, there are a lot of reasons why, but in the big picture it’s not unfair, it’s just the truth."
Since joining Mercedes in 2013, Hamilton has scored 74 race wins for the team.
When securing his seventh world title at the Turkish GP last year, Hamilton also took his 73rd win for Mercedes, surpassing the record held by Michael Schumacher for the most wins with a single team - 72 with Ferrari between 1996 and 2006.
Asked if criticism of his six-year partnership with Ferrari was unfair, given he ranks below only Schumacher  and Niki Lauda  in the number of races wins scored for the manufacturer with 14, he added: "It still doesn’t change anything. We still failed.
"We had the ambition and targets to win the championship and we didn’t. I think it’s just an honest reflection. I don’t think saying it out loud changed anything."
In joining Aston Martin for the upcoming season, Vettel will race alongside Canadian Lance Stroll.
Vettel is stating an obvious FACT. Hamilton ad Mercedes is probably the best driver team combination i history ad only an idiot would attempt to break up that combination. Just saying !!!
GPFans is a multi-platform, multi-language brand dedicated to Formula One coverage. We bring you all the ins and outs of the sport, 24/7, everything from up-to-the-minute news and features to the latest viral stories and clips.
We believe that a new generation of exciting, outspoken drivers will make F1 more popular than ever before, and we want to give our users access to as much of their heroes as possible, on and off the track. From Lewis Hamilton to Max Verstappen, Daniel Ricciardo to Sebastian Vettel, we provide in-depth analysis of every every Grand Prix in the season, from Australia to Abu Dhabi.
With Formula One under the new ownership of Liberty Media, how the sport is being covered is evolving, and GPFans will look to be at the heart of this progression into new media, as one of the fastest-growing sites covering the king of motorsports.