Former F1 driver Andre Lotterer says Red Bull boss Christian Horner's criticism of Formula E is actually a "compliment".
Horner said recently that the all-electric single seater series "doesn't work" because it "doesn't take people with it".
"There is no noise, there is no passion," he told the OMR podcast. "There is no atmosphere either.
"You can now see manufacturers withdrawing from the championship again."
But while Horner is right that Audi, BMW and Mercedes all headed for Formula E's exit door, Porsche driver Lotterer says Horner's criticism is "a compliment".
"It shows that Formula E is indirectly important to him," said the German. "But they are two different worlds that cannot be compared.
"The championship has a future and there are not many alternatives for manufacturers to present e-mobility," the 40-year-old, who contested a one-off F1 race for Caterham in 2014, added.
"If it didn't work, Formula E wouldn't be here," Lotterer insisted. "It was challenging at the beginning but the steps are big. We know what kind of performance electric cars can deliver.
"Combining that in motorsport is a cool story."
But it's on the issue of driver quality that Lotterer thinks actually puts Formula E ahead of the pinnacle of motorsport.
"Both series have top talent, but on average there is more in Formula E because they are all professionals and nobody brings money with them," he said.
"Everyone has earned their place through talent. A few drivers would have no place in Formula 1 without their (commercial) package."