Most of the better defenders at the point are just good at anticipating the passing lanes and keeping their hands active and disruptive.

Which, really, isn't that bad, in the grand scheme of things. Some turnovers leading to baskets can make up for the possessions when you let the other guy in the lane and hoped your big would dissuade him. It's just hard as shit for someone likely to be one of the smaller guys on the court to both facilitate the offense on every play and carry the burden of shutting down their facilitator every play on defense. Some of the better defenders can keep them on their toes... but "shut down" guys? Nah.

There aren't really "stoppers" at the point in college or the pros very often anymore. That job falls to 2 guards who sometimes guard the other team's point if the occasion calls for it.

Bledsoe's probably the closest. His commitment to defense and his sheer length make him a nightmare. Though I do wonder if he'd play defense as hard as he does if he was a 35+ minute per night starter... it's admittedly easier to focus on defense when the burden of offense isn't on you and you're brought in especially to defend.