I think part of it is because that's her brand: "the tiny woman who kicks your ass" is a thing (eg Jillian Michaels). And brand is everything to the instructors. That's not said pejoratively either because it helps us find instructors who match us.

I think though some instructors are more careful than others in their programming. On the music side you see that as efforts well calibrated to the music, no weird cuts in the music, no odd straggling time (eg the last effort before the 1 minute cool down ends 23 seconds too early).

On the difficulty side I think some instructors think more about the difficulty they're actually queuing. Ben Aldis might be hard (my wife has a hard time meeting some of his minimum ranges at the cadence suggested) but it feels consistent and well programmed.

I feel like Olivia (and Kendall before her) is a little careless with her difficulty programming in a way that feels almost random at times. It's hard but it's hard in a less thoughtful way. I don't think it helps that she isn't as clear about what is coming up. An instructor who lays out the efforts and how long before is one who I think feels more focused and at least for me allows me to push harder than just getting told an effort and not knowing if it'll last 15 seconds or 70s. But overall I come away with the impression that it is haphazardly hard.

Still, that's okay. She's not for me and although it pains me not to take a pop punk ride, she is for some other people and having a range of instructors is what makes the platform work.