How so?

Managing recoil and bullet travel time is a skill, that's for sure, but extreme precision is too. Best argument I can give is that one of the highest skilled FPS games out there, Quake, has no recoil and has hitscan on some of its weapons. Recoil and spread are usually in good balance for games with faster kill times, like CoD, Battlefield, Counter Strike... But in games where players can get stacked up on health and armor, and it can often take several seconds to kill your opponent? Having no recoil in those scenarios doesn't make it any less skill reliant.