It's hard to know how much leeway to give a sitcom when it comes to things that would be horrifying in real life but can seem merely goofy in the context of a television show. In real life, Robin would be justified in never speaking to either Ted or Barney ever again after they turn her hopes, her personality, her very life into a class. The show attempts to sweep that under the rug by having Ted frame it as a use for all the Robin knowledge he'd generated when they were dating, and that it's the hardest he'd ever seen barney work to keep a girl. It doubles down by having Barney apologize and attempt to explain himself. But it still feels a little strange for Robin to forgive the both of them so quickly for such a gross violation, even if the show bends over backwards to make the argument that it was well-meaning.
On the other hand, there are demands of a sitcom, chiefly that things be more-or-less reset to the status quo by the end of the episode. Even in a comedy as continuity-heavy and intertextual as How I Met Your Mother, there's a certain inertia of the familiar, where outside of the season finale or Big Event context, the basic dynamic of the group has to stay the same. With that in mind, I can, more or less, make my peace with it. It helps that beneath the inherent creepiness of the whole thing, Ted's class is pretty damn funny, from the brick joke with the Flatiron Building, to Barney being a less-than-model student, to the list of items that can distract Robin when she's mad. Marshall's barrel B-story is pretty slight by comparison, but as usual Jason Segel makes the most of it.
All-in-all, the laughs are there for the most part, even if some of the humor is broad. It's just a question of whether you can separate how horrific something like "Robin 101" would be in the real world from the silly tone it has in the heightened reality of HIMYM.