You don’t have to make ARs to know that they’re popular. We’ve known for a long time that they’re one of the best-selling guns on the market to the point where just about every major (and most minor) gun manufacturers makes them.
It’s not just ARs, but AKs and countless other models of rifles patterned off military designs but made for the commercial market are guaranteed best-sellers.
The National Shooting Sports Foundation, or NSSF, calls them “Modern Sporting Rifles,” an increasingly-popular moniker for these guns, or just MSRs. They have been tracking sales and ownership of MSRs since 2010 and news flash, they’re popular.