Former Ferrari technical director Aldo Costa believes "serious mistakes" regarding the team's vision and the hiring and firing of employees are to blame for their current woes.
The legendary Italian stable is once again unable to compete for top honours this season as they are well off the pace of leaders Mercedes and second-placed Red Bull.
They are likely to finish the campaign without any silverware, taking their Drivers' trophy drought to seven years while they last won the Constructors' crowns in 2008.
Costa spent 15 years at Maranello and was involved in the building of six Drivers' Championship-winning cars, but he was sacked in 2011 before joining Mercedes as an engineering director a few months later.
In an interview with Italian F1 journalist Leo Turrini, which has been translated by jamesallenonf1.com, he was quite outspoken about his former bosses.
"I'm not happy about it [their current struggles]. I worked for a company that is a myth. It doesn't please me to see how it is reduced, in Formula One terms, even though they fired me and in a way that I don't consider very elegant," he said.
"Let me say that there are a lot of people working in Maranello, for whom I feel affection and it pains me that they are in such a complicated situation. It is not good, I left many friends there, should I be happy to see them in such trouble?"
He added: "Strategic mistakes were made - I'm talking here about errors of vision - very serious ones. And of course they haven't always taken the best decisions regarding people.
"I'll give you an example. In 2008 we in the racing department put in a request to construct a new wind tunnel. We considered it essential to remain competitive. We were told that this was not the case and that there was no need.
"In Ferrari all the decisions, on strategy and people, have always been taken by the president, [Luca di] Montezemolo. To be fair, he took them when Ferrari was winning everything and he also took them when Ferrari stopped winning."
Fernando Alonso is widely regarded as one of the best drivers on the Formula One grid and, although he hailed the two-time World Champion's driving skills, Costa isn't impressed by the Spaniard away from the track.
"I consider Fernando a true great when he is in the car, driving. Out of the car, I was never able to understand him; to me he is an indecipherable character, an enigma," he said.
"However he will not be coming to us at Mercedes, I do not see why [Lewis] Hamilton should want to leave a team like ours."