Schumacher was dropped by Haas at the end of 2022, with the American team opting for a more experienced German driver in Nico Hulkenberg.
With Sebastian Vettel calling time on his career at the end of last year, Hulkenberg is the only German driver on the grid.
Tost - who has previously admitted that he wanted to sign Schumacher for Alpha Tauri - says he could have “become the new hero” for Germany.
“Mick’s career determines the interest in Germany,” Tost told Auto Bild. “Nico Hülkenberg cannot do it alone.
“They [the German public] wanted to see Michael Schumacher win back then and not the engine or the car from Mercedes. Only heroes trigger a boom. As Michael Schumacher showed.
“The second example is Boris Becker. Before him, interest in tennis was more reserved for the affluent citizens. That changed abruptly with the success of Boris and Steffi Graf. Suddenly all the kids wanted to play tennis.
“He could have become the new hero, but unfortunately he’s out of F1 for now. What a shame.”
Tost also thinks as a nation, Germany has been “spoiled” with their success in football, but also in F1 with Michael Schumacher.
“Germany is spoiled,” Tost added. “You can even feel it in football. I’m convinced that the lack of interest at the last World Cup also has something to do with the poor results of the national team.
“If they had reached the final, half of Germany would have followed the games in Qatar as well. One thing is certain: people need heroes, and they need them made of flesh and blood, not metal."