"I'm not a big country fan, but I am of that song," Simmons says of the country rap anthem.
While out at Craig's on Thursday, Simmons was asked if he felt the rapper's snub was "racially-charged."
"No. I don't think [so]," he replied. "I think they did purists, maybe."
Despite dominating the charts, Lil Nas X's hit with Billy Ray Cyrus wasn't recognized in any category for the awards show, which aired on Wednesday.
The song, which has been popular amongst country and hip-hop fans alike, has stirred up plenty of controversy because of the snub.
"I'm not a big country fan, but I am of that song," Simmons said. "I think it should be nominated because it's an amazing song. It should be [nominated] in all categories."
While Lil Nas X did not perform at CMT Music Awards, which took place in Nashville on June 5, the 20-year-old rapper did receive a shoutout by country group Little Big Town.
The band's members -- Karen Fairchild, Kimberly Schlapman, Philip Sweet and Jimi Westbrook -- who hosted the awards ceremony, sang a verse from "Old Town Road" at the start of the show and poked fun at the debate over what genre the song should be categorized as.
"Is 'Old Town Road' country or not?" Westbrook asked. Fairchild and Schlapman later added, "We love it!"
"Old Town Road" controversially was removed from the Billboard country charts earlier this year.
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