Winners of four successive drivers' and constructors' titles between 2010 and 2013, Red Bull have fallen behind as engine supplier Renault struggle to find performance and reliability.
Neither Ricciardo, nor Russian team mate Daniil Kvyat, have been on the podium this season and Red Bull are fourth overall ahead of their home Austrian Grand Prix at the Red Bull Ring.
"They take from us not only time and money but also the will and motivation," Mateschitz said of Renault in an interview with Speed Week Magazine.
"There is no driver and no chassis which is more able to compensate for the lack of horsepower. What else has to happen that we will lose our motivation completely?".
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Ricciardo, who was only 17th fastest in Friday's free practice and has a 10-place grid penalty for Sunday due to an engine change, said Mateschitz's comments were born of simple frustration.
"We’re now in the eighth race of the season so the frustration can start to build," he said.
"We know we’re still at a disadvantage. We were last year and obviously we were optimistic we’d close the gap a lot this year but nearly halfway through the season we’re more or less in the same position," added Ricciardo.
"I think this is where the comments and frustration came from."
The wave of negativity from Red Bull, at a time when the sport is discussing changes from 2017, has taken on a more concerted look this week with criticism from several quarters within the company.
Red Bull's motorsport consultant Helmut Marko and former Red Bull driver Mark Webber, in an interview released by the energy drinks company, have accused the sport of being over-regulated and dulled down.
On Friday, the front page of a special edition of the Red Bulletin magazine that is printed at the circuit and handed out in the paddock carried the headline "What's Wrong with Formula One?".
Inside, an article under the byline of triple world champion and Mercedes non-executive chairman Niki Lauda, a friend and compatriot of Mateschitz, argued the sport had "basically been regulated to death down the years".
"Everyone sticks their oar in," it added.
(Editing by Tony Jimenez)
