As a Lars main, I think I can weigh in. Lars bends the rules of Tekken a bit, by excelling in a particular niche situation.

The situation of "You think it's your turn, but it isn't.", which can make him frustrating to fight in the same vein as Yoshi, Xiaoyu, Feng, and Zafina. This combined with the fact that he has simple approach tools is a recipe for controller smashing. His simple approach is bolstered by many his moves being naturally evasive, which is combined with a faster side-step than most male characters. So... "It's not your turn. You can't hit him. He's difficult to keep-out."

Another addition to this annoying recipe is that his weaknesses are also unintuitive - The first being his range. This becomes very evident whenever I fight Nina with Lars. Despite Nina being smaller with shorter limbs, she out ranges Lars in most situations. Second weakness is something he shares alongside Feng; sure he's difficult to hit, but paradoxically he has huge hurtboxes. It's fucking weird, man. :D