It doesn't necessarily matter. They just don't like running after prey.

They can make swift dashes on land to catch prey sunbathing or something that's escaping, but that's the limits of what they'd like to do.

It's like Pandas. They're cute as hell, but if it wasn't for us, they'd have died out already. They've evolved themselves to a point where all they eat is one specific plant, and they have such a low sex drive that we can't even show them Panda Porn to get them horny. We literally have to extract sperm from their balls and inject it into the uterus of the female to make baby pandas.

Evolution is lazy is what I'm trying to say.