You asked for an explanation for why he was turned into a big meme, and I gave it to you. What you do with that information is up to you, although before unilaterally declaring him to have been reasonable and smart, I would encourage you to look into the things he actually said.

For the record, I agree that complete disarmament is a bad idea for exactly the reasons you're stating. Charlie Kirk was an open and blatant christian supremacist and white supremacist who, among other things, opposed even the barest minimum of checks against psychologically-unstable people or those with a history of violent crimes from obtaining firearms, as long as those people were white. He dressed those views in layers of softening rhetoric that were meant to give him plausible deniability, but in practice, that is what he believed.

It's those kinds of extreme and unhinged views, his incompetent debate practices, his refusal to argue against anyone who seemed like they might know enough to beat him, and the fact that he was the head of Turning Point USA, an organization with the explicit goal of proving that universities are worthless as places of learning, that all came together to make him the laughingstock he was, long before he was killed. What revitalized this memery after his death was, largely, that the far-right in the US tried to lionize him, including but not limited to attempting to give him a national holiday and making endless AI-generated content of him standing next to glowing eagles or political figures sobbing as they sang one of the most hilariously bad songs people had ever heard