Wrestling/no-gi BJJ doesn't have a gi, so players can't lock down their opponents as much and there's a lot more movement in neutral. And Judo has a gi, but the way you win is via high-amplitude throws, which is a much more spectacular win condition. I think they're both much more exciting to watch than regular gi BJJ, especially for non-practitioners.

I think BJJ's main spectator-unfriendly flaws are that it has a gi and doesn't reward high-amplitude movements. So, unsurprisingly, the metagame has evolved around locking down your opponents.

(Background: I did Judo as a kid, and do BJJ now.)

What really makes me appreciate it isn't knowing how to do it, it's more that the buddy who got me into it was very, very talented, and had retired into coaching at a gym, and before I ever stepped foot in a gym, we'd hang out, have some beers, and watch footage as he explained what was going on. At the professional level, it's quite nuanced and complex, like a chess match.