Affording to Jimmy Hoffa himself, he was intending to meet with two mafia leaders in Detroit. Given the crime levels present in the city, and the shady nature of the individuals he was meeting with, the circumstances are more than convincing that his disappearance was criminal in nature. Just because the two people he intended to meet with were not at the location of his disappearance does not provide evidence that they did not have a hand in the situation.
Yes, the 1975 kidnapping and disappearance of Jimmy Hoffa was caused by organized crime, because people just don't disappear. There were people who wanted him gone. Getting rid of Jimmy Hoffa was a big enough operation that they had to be a group of organized criminals in order to pull it off.
I definitely think that the mafia or mob had a hand in the disappearance of Jimmy Hoffa in 1975. Jimmy Hoffa was somebody who was a controversial figure and created a lot of enemies. It is only logical to think that the odd circumstances surround his kidnapping and disappearance had something to do with organized crime.
The Genovese crime family, long associated with Hoffa's connections to the mob, were the last people to see Jimmy Hoffa alive according to an eyewitness account. Hoffa was last seen in the back seat of Joe Giacalone's maroon Mercury Marquis on the afternoon of June 30, 1975. Hoffa tried to leave his mob connections behind and couldn't. Two mob bosses were supposed to meet Hoffa in Michigan, according to the man's wife. Yet both mobsters denied ever scheduling a meeting with the former Teamster's president. Hoffa's body's whereabouts has been an unsolved mystery for nearly 40 years.
The disappearance of Jimmy Hoffa in 1975 can be attributed to organized crime rather than labor unions or some other explanation. It's likely that he was abducted by criminals on purpose. These criminals orchestrated his disappearance in order to gain financially and in other ways that we might not know of.